Exhibit 99.1

Contact Information:

LOOPNET, INC. ANNOUNCES FOURTH QUARTER AND FISCAL 2011

FINANCIAL RESULTS

SAN FRANCISCO, CALIF. – February 22, 2012 – LoopNet, Inc. (NASDAQ: LOOP), today announced financial results for the fourth quarter and year ended December 31, 2011.

LoopNet’s revenue for the fourth quarter of 2011 was $22.1 million, compared to $20.0 million in the fourth quarter of 2010. Net loss applicable to common stockholders for the fourth quarter of 2011 was $2.7 million or $0.07 per diluted share, compared to net income applicable to common stockholders of $7.2 million or $0.17 per diluted share in the fourth quarter of 2010. Net loss applicable to common stockholders for the fourth quarter of 2011 included merger related costs of $7.5 million or $0.11 per diluted share, and an impairment charge related to an equity investment of $1.7 million or $0.03 per diluted share. Net income applicable to common stockholders for the fourth quarter of 2010 included a positive tax adjustment of $5.4 million or $0.13 per diluted share related to the reversal of the income tax valuation allowance for certain federal and state net operating loss carryforwards, an insurance reimbursement for litigation related fees of $750,000 or $0.01 per diluted share, and an impairment charge related to an equity investment of $1.4 million or $0.02 per diluted share. Excluding the above items net income applicable to common stockholders for the fourth quarter of 2011 was $0.07 per diluted share, compared to $0.05 per diluted share in the fourth quarter of 2010.

Non-GAAP net income, which excludes stock-based compensation, merger related costs, impairment charges, litigation related recoveries, amortization of acquired intangible assets and certain tax adjustments, for the fourth quarter of 2011 was $4.8 million or $0.11 per diluted share, compared to $4.0 million or $0.10 per diluted share in the fourth quarter of 2010.

LoopNet’s Adjusted EBITDA (earnings before net interest and other income (expense), income taxes, depreciation, amortization, stock-based compensation, merger related costs and litigation related recoveries) for the fourth quarter of 2011 was $7.8 million, compared to $7.0 million in the fourth quarter of 2010.

Revenue for the full year of 2011 was $86.7 million, compared to $78.0 million in 2010. Net income applicable to common stockholders for the full year of 2011 was $1.8 million or $0.04 per diluted share, compared to $15.4 million or $0.36 per diluted share in 2010. Net income applicable to common stockholders for the full year of 2011 included merger related costs of $11.7 million or $0.17 per diluted share, and an impairment charge related to an equity investment of $1.7 million or $0.03 per diluted share. Net income applicable to common stockholders for the full year of 2010 included a positive tax adjustment of $5.4 million or $0.13 per diluted share related to the reversal of the income tax valuation allowance for certain federal and state net operating loss carryforwards, insurance reimbursements for litigation related fees of $1.9 million or $0.03 per diluted share, and an impairment charge related to an equity investment of $1.4 million or $0.02 per diluted share. Excluding the above items net income applicable to common stockholders for the full year of 2011 was $0.24 per diluted share, compared to $0.22 per diluted share in 2010. Non-GAAP net income for the full year of 2011 was $17.6 million or $0.40 per diluted share, compared to $16.5 million or $0.39 per diluted share in 2010. Adjusted EBITDA for the full year of 2011 was $29.5 million compared to $28.4 million in 2010.

Key operating metrics and business highlights from the fourth quarter of 2011 include:

Balance Sheet and Liquidity

As of December 31, 2011, LoopNet had $111.1 million of cash, cash equivalents and short-term investments and no debt.

Pending Merger Transaction

The proposed acquisition of LoopNet by the CoStar Group, Inc. (“CoStar”) is currently under review by the Federal Trade Commission (the “FTC”). As previously announced on January 3, 2012, LoopNet and CoStar have voluntarily agreed to extend the waiting period imposed by the Hart-Scott-Rodino Act on a 45-day rolling basis to allow them to engage in discussions with the FTC to determine whether there is a possible basis for, and to discuss the possible terms of, a mutually acceptable consent order that would allow the merger to close. While there can be no assurance that agreement on the terms of a possible consent order can be reached in a timely manner or at all, LoopNet believes the discussions with the FTC Staff are currently proceeding constructively and LoopNet is hopeful that they will in the near term result in an agreement with the FTC Staff on the terms of such a consent order, subject to FTC approval. The proposed acquisition of LoopNet remains subject to the expiration or termination of the waiting period imposed by the Hart-Scott-Rodino Act and other customary closing conditions.

Use of Non-GAAP Financial Measures

This press release includes discussions of Adjusted EBITDA, non-GAAP net income and non-GAAP net income per share, which are non-GAAP financial measures provided as a complement to results provided in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The term “Adjusted EBITDA” refers to a financial measure that we define as earnings before income taxes, depreciation, amortization, net interest and other income (expense), litigation related recoveries, stock-based compensation, merger related stock-based compensation and other merger related costs. The term “non-GAAP net income” refers to a financial measure that we define as net income before litigation related recoveries, impairment of equity investments, stock-based compensation, merger related stock-based compensation, other merger related costs, amortization of acquired intangible assets and certain tax adjustments. Non-GAAP net income is also provided on a per share basis, using shares outstanding at the relevant period of measurement. Adjusted EBITDA, non-GAAP net income and non-GAAP net income per share are not substitutes for measures determined in accordance with GAAP, and may not be comparable to Adjusted EBITDA, non-GAAP net income and non-GAAP net income per share as reported by other companies. We believe Adjusted EBITDA to be relevant and useful information to our investors as this measure is an integral part of our internal management reporting and planning process and is the primary measure used by our management to evaluate the operating performance of our business. The components of Adjusted EBITDA include the key revenue and expense items for which our operating managers are responsible and upon which we evaluate their performance, and we also use Adjusted EBITDA for planning purposes and in presentations to our board of directors. We believe non-GAAP net income and non-GAAP net income per share to be relevant and useful information to our investors as they provide meaningful insight into our performance while excluding infrequent and non-recurring items that may not be considered directly related to our on-going business operations. We believe that non-GAAP net income and non-GAAP net income per share are also used by companies and investors to evaluate comparable performance in the online marketplace and platform industry. We also believe that Adjusted EBITDA, non-GAAP net income and non-GAAP net income per share allow for a more accurate comparison of our operating results over historical periods. A limitation of Adjusted EBITDA, non-GAAP net income and non-GAAP net income per share is that they do not include all items that impact our net income for the period. Management compensates for this limitation by also relying on the comparable GAAP financial measure of net income, which includes the items that are excluded from Adjusted EBITDA, non-GAAP net income and non-GAAP net income per share. Management believes that these non-GAAP measures should be considered as a complement to, and not as a substitute for, or superior to, the corresponding measures calculated in accordance with GAAP. A reconciliation of these non-GAAP measures to GAAP is provided in the attached tables.

About LoopNet, Inc.

LoopNet operates the most heavily trafficked commercial real estate marketplace online with more than 5 million registered members and more than 2 million unique monthly visitors, as reported by Google Analytics.

The LoopNet marketplace covers all commercial property categories, including office, industrial, retail, multifamily (apartment properties for sale), hotel, land, specialty properties, investment properties and businesses for sale. LoopNet customers include virtually all of the top commercial real estate firms in the U.S., including CB Richard Ellis, Cassidy Turley, Coldwell Banker Commercial, Colliers International, Cushman & Wakefield, Grubb & Ellis, Jones Lang LaSalle, Lincoln Property Company, NAI Global, Newmark Knight Frank, ProLogis, The Shopping Center Group and Sperry Van Ness.

Forward Looking Statements

This release contains forward-looking statements regarding our financial results and the Merger. These statements are based on current information and expectations that are inherently subject to change and involve a number of risks and uncertainties. Actual events or results might differ materially from those in any forward-looking statement due to various factors. The following factors related to the Merger, among others, could cause or contribute to such differences: the possibility that the FTC will request additional extensions to the waiting period imposed by the HSR Act; the possibility that LoopNet, CoStar and the FTC cannot reach a mutually acceptable resolution in a timely manner or at all; the possibility that conditions, divestitures or changes relating to the operations or assets of LoopNet and CoStar will be required to obtain required governmental clearances or approvals, including, but not limited to, clearance or approval by the FTC; the possibility that the Merger does not close, including, but not limited to, due to the failure to obtain governmental clearances or approvals; the risk that expected cost savings or other synergies from the Merger may not be fully realized or may take longer to realize than expected; the risk that the businesses of LoopNet and CoStar may not be combined successfully or in a timely and cost-efficient manner; the risk that business disruption relating to the Merger may be greater than expected; and the failure by CoStar to obtain any required financing on favorable terms.

In addition, the following factors, among others, could also cause results to differ materially from those anticipated in the forward-looking statements: economic events or trends in the commercial real estate market or in general; the effects of recent economic and consumer confidence trends on global and domestic financial markets, including credit available to real estate purchasers; our ability to continue to attract and retain new registered members, convert registered members into premium members and retain such premium members; seasonality; our ability to manage our growth; our ability to successfully integrate the technologies, operations and personnel of acquired businesses in a timely manner; our ability to obtain the expected strategic and financial benefits from acquisitions; our ability to introduce new or upgraded products or services and customer acceptance of such services; and our ability to obtain or retain listings from commercial real estate brokers, agents and property owners.

Additional information concerning factors that could cause actual events or results to differ materially from those in any forward looking statement are contained in our Annual Report on Form 10-K and Quarterly Reports on Form 10-Q filed with the Securities and Exchange Commission (“SEC”), and other SEC filings made by us. Copies of filings made by us with the SEC are available on the SEC’s website or at http://investor.loopnet.com/sec.cfm. LoopNet does not intend to update the forward-looking statements included in this press release which are based on information available to us as of the date of this release.

LOOPNET, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(In thousands, except share data)

LOOPNET, INC.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except per share data)

(unaudited)

LOOPNET, INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

(unaudited)

LOOPNET, INC.

Reconciliation of GAAP Net Income (Loss) to Adjusted EBITDA

(In thousands, except per share data)

Reconciliation of GAAP Net Income (Loss) to Non-GAAP Net Income

(In thousands, except per share data)