Exhibit 99.1

Investor and Media Contact

Christy Linn
Director, Investor Relations and Corporate Communications
214.466.1825
christy.linn@archlearning.com

ARCHIPELAGO LEARNING REPORTS SECOND QUARTER 2011 RESULTS
Revenue Grew for the 14th Consecutive Quarter
Reiterating Full Year 2011 Revenue Guidance; Operating Cost Outlook Improves
ESL Acquisition Strengthens Product Offerings

DALLAS, Texas — August 9, 2011 — Archipelago Learning, Inc. (NASDAQ: ARCL), a leading subscription-based, software-as-a-service (SaaS) provider of education products, today announced its financial results for the second quarter ended June 30, 2011.

Second Quarter 2011 Highlights:

	•		Revenue grew 34.5 percent to $18.3 million
	•		Invoiced sales rose 11.6 percent to $17.5 million
	•		Cash EBITDA of $5.7 million and diluted EPS of $0.07

Six Months Ended 2011 Highlights:

	•		Revenue grew 36.1 percent to $35.6 million
	•		Invoiced sales rose 25.3 percent to $32.9 million
	•		Cash EBITDA of $8.9 million and diluted EPS of $0.10
	•		Cash flows from operating activities and free cash flow were $7.5 million and $6.0 million, respectively

“We continue to perform well and are energized by the resilience of our customers and the tenacity of our sales organization given the difficult operating environment,” said Tim McEwen, Chairman, President and Chief Executive Officer of Archipelago Learning. “Although the funding uncertainty resulting from delayed budget approvals in some of our largest states, such as Texas and Pennsylvania, put pressure on invoiced sales during the second quarter, 60 percent of our top 15 states recorded year-over-year invoiced sales growth of Study Island products.”

He went on to say, “Additionally, we are pleased that second quarter customer commitments began to translate into invoiced sales in July, which resulted in us posting a monthly sales record. We continue to be cautiously optimistic as we move into August and September and focus on orders in our key states.”

McEwen concluded, “As we move into our busiest selling quarter of the year, we are focused on delivering our high-impact, low-cost, fully-digital value proposition to customers as a trusted partner in the classroom. We believe that our core product enhancements, the addition of our English as a Second Language (ESL) product, ESL ReadingSmart, and our web platform upgrade

demonstrate our commitment to addressing the evolving needs of our customers and being a leader in K-12 education digital solutions.”

Financial Summary Table (Table 1)

		Quarter ended June 30,																Six months ended June 30,
										$				%												$				%
($ in thousands, except EPS)		2011				2010				Change				Change				2011				2010				Change				Change
Revenue		$	18,288			$	13,597			$	4,691				34.5	%		$	35,590			$	26,146			$	9,444				36.1	%
Invoiced sales			17,536				15,707				1,829				11.6				32,934				26,278				6,656				25.3
Royalties on invoiced sales			(165	)			—				(165	)		NM					(276	)			—				(276	)		NM
Operating costs(1)			(14,278	)			(12,992	)			(1,286	)			9.9				(29,066	)			(21,557	)			(7,509	)			34.8
Depreciation and amortization			1,565				903				662				73.3				3,047				1,602				1,445				90.2
Stock-based compensation(2)			557				520				37				7.1				1,843				928				915				98.6
Unusual, non-recurring charges(3)			440				3,290				(2,850	)			(86.6	)			440				3,293				(2,853	)			(86.6	)
Cash EBITDA(4)			5,655				7,428				(1,773	)			(23.9	)%			8,922				10,544				(1,622	)			(15.4	)%
Net income			1,799				(145	)			1,944			NM					2,789				1,922				867				45.1	%
Diluted EPS		$	0.07			$	(0.01	)		$	0.08			NM				$	0.10			$	0.08			$	0.02				25.0	%
Cash flows from operating activities																		$	7,526			$	4,161			$	3,365				80.9	%
Purchase of property and equipment																			(1,525	)			(424	)			(1,101	)			259.7
Free cash flow																		$	6,001			$	3,737			$	2,264				60.6	%

Second Quarter 2011 Summary

Second quarter 2011 revenue was $18.3 million, an increase of $4.7 million, or 34.5 percent compared with the same period a year ago. Deferred revenue at June 30, 2011 rose 19.6 percent to $56.7 million, compared with $47.4 million at June 30, 2010. The increase in revenue and deferred revenue were driven by the acquisition of EducationCity in June 2010 and higher invoiced sales recorded by our core business over previous periods. For the second quarter 2011, invoiced sales were $17.5 million, an increase of $1.8 million, or 11.6 percent, over the second quarter in 2010. This increase was due to the acquisition of EducationCity.

Operating costs (operating expenses plus cost of revenue) for the second quarter 2011 were $14.3 million compared with $13.0 million for the second quarter 2010. The increase was due to the full-year impact of the integration of EducationCity along with the strategic investments we are undertaking during 2011 (see Table 2), and was partially offset by acquisition costs for EducationCity incurred in June 2010. Additionally, depreciation and amortization increased $662 thousand primarily due to EducationCity purchase accounting.

Incremental Costs Summary (Table 2)

		Original				Revised								FY 2011
		FY 2011				FY 2011				YTD Q2				Remaining
($ in thousands)		Guidance				Guidance				2011				Investment
Global (EducationCity acquisition)(5)		$	7,000			$	6,200			$	5,700			$	500
Content and 100% digital			3,500				2,500				1,055				1,445
Sales generation and infrastructure			4,500				4,300				1,850				2,450
Total incremental investment		$	15,000			$	13,000			$	8,605			$	4,395

Cash EBITDA for the second quarter ended June 30, 2011 was $5.7 million versus $7.4 million in the second quarter ended June 30, 2010 primarily due to higher operating costs.

For the second quarter 2011, net income was $1.8 million compared with a net loss of $145 thousand for the second quarter 2010, and diluted earnings per share (EPS) were $0.07 compared with a loss of $0.01 per share for the same period a year ago. The increase was primarily due to acquisition costs for EducationCity that decreased second quarter 2010 net income and EPS.

Balance Sheet and Cash Flows Update

Cash and cash equivalents totaled $36.3 million, availability under our revolving credit facility was $20.0 million, and total debt was $75.3 million at June 30, 2011. For the six months ended June 30, 2011, our cash flows from operating activities were $7.5 million compared with $4.2 million for the first six months of the previous year. Given our current cash position, solid cash flow generation and available capacity under our existing credit facility, we believe we have significant balance sheet flexibility.

Fiscal 2011 Outlook

Archipelago Learning is reiterating the following fiscal year 2011 estimates, which reflect the full year impact of the EducationCity acquisition:

	•		Revenue is projected to be in the range of $68 million to $72 million;
	•		Cash EBITDA is estimated to be between $30 million and $34 million;
	•		Cash flows from operating activities are projected to be in the range of $23 million to $27 million;
	•		Capital expenditures are expected to be between $4 million and $5 million, primarily driven by the reinvestment in our software technology platforms and infrastructure; and,
	•		Free cash flow is anticipated to be in the range of $19 million to $23 million. We define free cash flow as cash flows from operating activities less purchase of property and equipment.

Additionally, we are revising our fiscal year 2011 operating costs outlook, which are now expected to be between $60 million and $62 million. The slightly lower estimated range for our operating costs reflects $2

million in costs savings related to both operations of EducationCity and cost efficiencies realized in our strategic investments in 2011.

Operating Costs Summary (Table 3)

										FY 2011
						non-GAAP				Original				Revised
		FY 2010				FY 2010				Guidance				Guidance
		as Reported				Reconciliation				Reconciliation				Reconciliation
Operating costs (excluding depreciation and amortization, stock-based compensation and unusual, non-recurring charges)		$	—			$	38,752			$	38,752			$	38,752
Depreciation & amortization			—				4,396				6,000				6,000
Stock-based compensation(2)			—				1,762				3,400				3,400
Operating costs (excluding unusual, non-recurring charges)			—				44,910				48,152				48,152
Unusual, non-recurring charges(3)			—				4,803				300				440
FY 2011 additional investment			—				—				15,000				13,000
Total operating costs(1)		$	49,713			$	49,713			$	63,452			$	61,592

Conference Call Information

Archipelago Learning will host a conference call and webcast to discuss the results today at 4:45 p.m. ET, which will be hosted by Tim McEwen, Chairman, President and Chief Executive Officer, and Mark S. Dubrow, Chief Financial Officer. Investors and analysts interested in participating in the call are invited to dial (719) 325-2100 approximately ten minutes prior to the start of the call. Alternatively, the live webcast can be accessed via our website at http://investor.archipelagolearning.com. Please visit the website at least 15 minutes prior to the call to register for the webcast and download any necessary software.

About Archipelago Learning

Archipelago Learning (NASDAQ:ARCL) is a leading subscription-based, software-as-a-service (SaaS) provider of education products used by approximately 14 million students in nearly 38,700 schools throughout the United States, Canada, and the United Kingdom. Our comprehensive digital supplemental product suite uses technology to transform education. We make rigorous learning fun, engaging, accessible, and affordable. For more information, please visit us at www.archipelagolearning.com.

Forward Looking Statements

This release and the related conference call contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, Section 21E of the Securities Exchange Act of 1934, as amended, and the Private Securities Litigation Reform Act of 1995. All statements other than statements of historical fact, including, but not limited to, statements about our future performance and our guidance are considered forward-looking statements and reflect current expectations and projections relating to our financial condition, results of operations, plans, objectives, future performance and business as of August 9, 2011. The words “guidance,” “anticipate,” “estimate,” “expect,” “project,” “plan,” “intend,” “believe,” “may,” “should,” “likely,” “future,” and other words and terms of similar meaning are used to identify forward-looking statements. These forward-looking statements are based on assumptions that we have made in light of our industry experience and on our perceptions of historical trends, current conditions, expected future developments and other factors we believe are appropriate under the circumstances.

These statements are not guarantees of performance or results and are subject to risks and uncertainties (some of which are beyond our control), which could cause actual results to vary materially from the forward-looking statements contained in this release. Although we believe that these forward-looking statements are based on reasonable assumptions, many factors could cause actual results to vary materially from those anticipated in such forward-looking statements. Certain risk factors are discussed in the Company’s filings with the Securities and Exchange Commission and include, but are not limited to (i)

our customers’ reliance on, and the availability of, state, local and federal funding; (ii) competitive factors, including large publishers aggressively entering our markets and new competitors more easily entering our markets if national educational standards are adopted; (iii) legislation and regulation, including changes in or the repeal of legislation that mandates state educational standards and annual assessments; (iv) difficulty in evaluating our current and future business prospects because of our recent rapid growth; (v) web-based education failing to achieve widespread acceptance by students, parents, teachers, schools and other institutions; (vi) lower customer renewal rates or a decrease in sales for our Study Island products; (vii) decisions at district or state levels to use our competitors’ products rather than ours; (viii) seasonal fluctuations; (ix) system or network disruptions and technology issues; (x) delays in product development or product releases and the success of new product introductions; (xi) acquisition related risks; (xii) intellectual property related risks; (xiii) our ability to retain key employees; (xiv) risks related to our indebtedness; (xv) legal risks; (xvi) risks related to global and U.S. economic conditions; and, (xvii) risks associated with the integration of EducationCity and Alloy Multimedia and the future performance of our EducationCity and ESL ReadingSmart products.

Any forward-looking statement speaks only as of the date on which it is made, and the Company undertakes no obligation to update any forward-looking statements to reflect new information, future developments or otherwise, except as may be required by law.

Table 4

ARCHIPELAGO LEARNING, INC.
CONDENSED CONSOLIDATED STATEMENTS OF INCOME — (UNAUDITED)
(in thousands, except share and per share data)

		Three Months Ended												Three Months Ended
		June 30,								%				June 30,
		2011				2010				Change				2011				2010
														As a % of revenue
Revenue		$	18,288			$	13,597				34.5	%			100.0	%			100.0	%
Cost of revenue			1,362				1,029				32.4				7.4				7.6
Gross profit			16,926				12,568				34.7				92.6				92.4
Operating expense:
Sales and marketing			5,505				4,146				32.8				30.1				30.5
Content development			1,703				1,226				38.9				9.3				9.0
General and administrative			5,708				6,591				(13.4	)			31.2				48.5
Total			12,916				11,963				8.0				70.6				88.0
Operating income			4,010				605				562.8				21.9				4.4
Other income (expense):
Interest expense			(1,105	)			(879	)			(25.7	)			(6.0	)			(6.5	)
Interest income			79				150				(47.3	)			0.4				1.1
Foreign exchange loss			(16	)			(99	)			83.8				(0.1	)			(0.7	)
Derivative loss			—				27				(100.0	)			—				0.2
Total			(1,042	)			(801	)			(30.1	)%			(5.7	)			(5.9	)
Income before tax			2,968				(196	)			NM				16.2				(1.4	)
Provision for income tax			1,169				(51	)			NM				6.4				(0.4	)
Net income		$	1,799			$	(145	)			NM				9.8	%			(1.1)	%
Earnings per share:
Basic		$	0.07			$	(0.01	)			NM
Diluted		$	0.07			$	(0.01	)			NM
Weighted-average shares outstanding:
Basic			25,406,664				24,181,680
Diluted			25,573,166				24,181,680

Table 5

ARCHIPELAGO LEARNING, INC.
CONDENSED CONSOLIDATED STATEMENTS OF INCOME — (UNAUDITED)
(in thousands, except share and per share data)

		Six Months Ended												Six Months Ended
		June 30,								%				June 30,
		2011				2010				Change				2011				2010
														As a % of revenue
Revenue		$	35,590			$	26,146				36.1	%			100.0	%			100.0	%
Cost of revenue			3,069				1,942				58.0				8.6				7.4
Gross profit			32,521				24,204				34.4				91.4				92.6
Operating expense:
Sales and marketing			11,426				7,968				43.4				32.1				30.5
Content development			3,410				2,267				50.4				9.6				8.7
General and administrative			11,161				9,380				19.0				31.4				35.9
Total			25,997				19,615				32.5				73.0				75.0
Operating income			6,524				4,589				42.2				18.3				17.6
Other income (expense):
Interest expense			(2,197	)			(1,649	)			(33.2	)			(6.2	)			(6.3	)
Interest income			149				303				(50.8	)			0.4				1.2
Foreign exchange loss			(137	)			(99	)			38.4				(0.4	)			(0.4	)
Derivative loss			—				(46	)			(100.0	)			—				(0.2	)
Total			(2,185	)			(1,491	)			(46.5	)			(6.1	)			(5.7	)
Income before tax			4,339				3,098				40.1				12.2				11.8
Provision for income tax			1,550				1,176				31.8				4.4				4.5
Net income		$	2,789			$	1,922				45.1	%			7.8	%			7.4	%
Earnings per share:
Basic		$	0.11			$	0.08				37.5	%
Diluted		$	0.10			$	0.08				25.0	%
Weighted-average shares outstanding:
Basic			25,393,977				24,019,902
Diluted			25,601,072				24,403,727

Table 6

ARCHIPELAGO LEARNING, INC.
CONDENSED CONSOLIDATED BALANCE SHEETS — (UNAUDITED)
(in thousands, except share data)

		As of				As of
		June 30,				December 31,
		2011				2010
Assets
Current assets:
Cash and cash equivalents		$	36,307			$	32,398
Accounts receivable, net			9,560				10,807
Deferred tax assets			3,543				3,463
Prepaid expenses and other current assets			2,399				3,560
Total			51,809				50,228
Property and equipment, net			4,536				3,760
Goodwill			168,665				165,694
Intangible assets, net			35,740				37,290
Investment			6,446				6,446
Notes receivable			2,041				1,934
Other long-term assets			1,387				1,610
Total assets		$	270,624			$	266,962
Liabilities and Stockholders’ Equity
Current liabilities:
Accounts payable — trade		$	773			$	928
Accrued employee-related expenses			2,394				2,518
Other accrued expenses			1,178				1,247
Taxes payable			1,351				979
Deferred tax liabilities			213				384
Deferred revenue			41,522				44,733
Current portion of note payable to related party			2,425				2,352
Current portion of long-term debt			850				850
Other current liabilities			640				463
Total			51,346				54,454
Long-term deferred tax liabilities			15,936				15,478
Long-term deferred revenue			15,161				14,312
Long-term debt, net of current			74,488				74,913
Other long-term liabilities			882				488
Total liabilities			157,813				159,645
Commitments and contingencies
Stockholders’ equity:
Preferred stock ($0.001 par value, 10,000,000 shares authorized, none issued and outstanding at June 30, 2011 and December 31, 2010)			—				—
Common stock ($0.001 par value, 200,000,000 shares authorized, 26,335,720 and 26,354,198 shares issued and outstanding at June 30, 2011 and December 31, 2010, respectively)			26				26
Additional paid-in capital			97,277				95,395
Accumulated other comprehensive income			2,354				1,531
Retained earnings			13,154				10,365
Total stockholders’ equity			112,811				107,317
Total liabilities and stockholders’ equity		$	270,624			$	266,962

Table 7

ARCHIPELAGO LEARNING, INC.
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS — (UNAUDITED)
(in thousands)

		Six Months Ended June 30,
		2011				2010
Cash flows from operating activities:
Net income		$	2,789			$	1,922
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of debt financing costs			223				149
Depreciation and amortization			3,047				1,602
Stock-based compensation			1,843				928
Unrealized gain on interest rate swap			—				(617	)
Deferred income taxes			121				1,041
Deferred rent			387				—
Loss on disposal of assets			11				—
Changes in operating assets and liabilities, net of acquisition:
Accounts receivable			1,235				317
Prepaid expenses and other			1,171				(1,194	)
Accounts payable and accrued expenses			(351	)			(136	)
Deferred revenue			(2,766	)			132
Other long-term liabilities			(184	)			17
Net cash provided by operating activities(6)			7,526				4,161
Cash flows from investing activities:
Acquisitions, net of cash acquired			(1,978	)			(61,300	)
Purchase of property and equipment			(1,525	)			(424	)
Net cash used in investing activities			(3,503	)			(61,724	)
Cash flows from financing activities:
Proceeds from supplemental term loan			—				15,000
Proceeds from revolver			—				10,000
Payment of debt financing costs			—				(804	)
Tax distributions to members			21				—
Purchase of common stock from ESPP			18				3
Payment of offering costs			—				(1,460	)
Payments on term note			(425	)			(388	)
Net cash provided by (used in) financing activities			(386	)			22,351
Effect of foreign exchange on cash and cash equivalents			272				225
Net change in cash and cash equivalents			3,909				(34,987	)
Beginning of period			32,398				58,248
End of period		$	36,307			$	23,261

Non-GAAP Financial Measures

This press release contains the following non-GAAP financial measures: invoiced sales, non-GAAP operating costs, cash EBITDA, and free cash flow. Because these financial measures are not recognized under GAAP, they should not be used as indicators of, or alternatives to, the corresponding GAAP financial measures of operating performance.

	•		We recognize invoiced sales in the period in which the purchase order or other evidence of an arrangement is received and the invoice is issued, which may be at a different time than the commencement of the subscription. Under GAAP, revenue for invoiced sales is deferred and recognized ratably over the subscription term beginning on the commencement date of the applicable subscription. This difference between non-GAAP invoiced sales and revenue in a given period is equal to the change in the Company’s deferred revenue balance for that period.
	•		Non-GAAP operating costs are defined as cost of revenue plus operating expenses.
	•		Cash EBITDA aligns with our management performance-based compensation metric, and is defined by invoiced sales less royalties, operating expenses and cost of revenue, excluding stock-based compensation, depreciation and amortization, and unusual, non-recurring charges.
	•		Stock-based compensation is part of our strategy and is used to attract and retain key employees and executives. It is principally aimed at aligning their interests with those of our stockholders and at long-term employee retention, rather than to motivate or reward operational performance for any particular period. Thus, stock-based compensation expense varies for reasons that are generally unrelated to operational decisions and performance in any particular period.
	•		Depreciation and amortization is included in our operating expenses in accordance with GAAP. Depreciable assets includes: computer equipment and software, furniture and fixtures, office equipment, and leasehold improvements. Amortization includes: customer relationships, technical development/program content, and non-compete agreements. We exclude these items from our non-GAAP financial measures because they are non-cash expenses that we do not consider part of ongoing operating results when assessing the performance of our business, and we believe that doing so facilitates comparisons to our historical operating results and to the results of other companies in our industry, which have their own unique acquisition histories.
	•		Free cash flow is defined as cash flows from operating activities less purchase of property and equipment and is cash available for management’s discretionary use to reinvest in the business, pay down outstanding debt and/or distribute to shareholders.

Reconciliation tables of GAAP to non-GAAP financial measures for invoiced sales, non-GAAP operating costs, cash EBITDA, and free cash flow are included in this release.

Management believes that these non-GAAP measures provide useful information to investors regarding certain financial and business trends relating to our financial condition and results of operations. Although management uses these non-GAAP financial measures to assess the operating performance of our business, they have significant limitations as an analytical tool because they may exclude certain material costs. For example, because cash EBITDA does not account for certain expenses, its utility as a measure of operating performance has material limitations. In addition, the definitions of non-GAAP financial measures may vary among companies and industries, and may not be comparable to other similarly titled measures used by other companies.

Table 8

ARCHIPELAGO LEARNING, INC.
RECONCILIATIONS OF NON-GAAP MEASURES — (UNAUDITED)
(in thousands)

		Three Months Ended								Six Months Ended
		June 30,								June 30,
		2011				2010				2011				2010
Net Invoiced Sales:
New customers		$	3,809			$	4,079			$	7,727			$	7,576
Existing customers			13,330				11,368				24,332				18,102
Other sales			397				260				875				600
Total			17,536				15,707				32,934				26,278
Royalties on invoiced sales			(165	)			—				(276	)			—
Change in deferred revenue(7)			918				(2,110	)			2,932				(132	)
Revenue		$	18,289			$	13,597			$	35,590			$	26,146
Adjusted Revenue:
Revenue		$	18,289			$	13,597			$	35,590			$	26,146
Impact of purchase accounting adjustment to deferred revenue(8)			599				227				1,359				227
Adjusted revenue		$	18,888			$	13,824			$	36,949			$	26,373