UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the Securities
Exchange Act of 1934 (Amendment No.  )

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o		Preliminary Proxy Statement
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o		Definitive Proxy Statement
þ		Definitive Additional Materials
o		Soliciting Material Pursuant to §240.14a-12

 

CORESITE REALTY CORPORATION

(Name of Registrant as Specified In Its Charter)

 

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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1050 17th Street, Suite 800
Denver, Colorado 80265

May 5, 2011

Dear Fellow Stockholder,

You recently received proxy materials in connection with the Annual Meeting of Stockholders to be held on Thursday, May 19, 2011, at 1:00 p.m., Mountain Time and according to our latest records, your PROXY VOTE for this meeting HAS NOT YET BEEN RECEIVED.

Coresite Realty Corporation is asking stockholders to vote on a number of important proposals. Please refer to the proxy materials previously mailed to you for additional information.

The Board recommends that you vote “FOR” the election of directors, “FOR” the ratification of KPMG LLP, “FOR” the advisory vote on executive compensation and “EVERY THREE YEARS” with regard to the advisory vote on the frequency of the advisory vote on executive compensation.

Regardless of the number of shares you own, it is important that they be represented at the annual stockholders meeting. Your vote matters to us and we need your support.

Please vote your shares now so that your vote can be counted without delay. Voting is easy. You may utilize one of the options below to ensure that your vote is promptly recorded in time for the special stockholders meeting:

	•		VOTE BY TOUCHTONE PHONE: You may cast your vote by calling the toll-free number on the enclosed proxy card. Follow the instructions on your proxy card to cast your ballot.
	•		VOTE THROUGH THE INTERNET: You may cast your vote by logging into the Internet address located on the enclosed proxy card and follow the instructions on the website.
	•		VOTE BY MAIL: You may cast your vote by mail by signing, dating and mailing the enclosed proxy card in the postage-prepaid return envelope provided.

YOUR PARTICIPATION IS IMPORTANT — PLEASE VOTE TODAY!

If you have any questions with regards to voting your shares, you may call our proxy solicitation advisors, Eagle Rock Proxy Advisors, LLC. Toll-Free at (855)-612-6971 between the hours of 9:00 a.m. and 10:00 p.m. Eastern Time, Monday through Friday.

We appreciate your support.

IF YOU HAVE RECENTLY MAILED YOUR PROXY OR CAST YOUR VOTE BY PHONE OR OVER THE
INTERNET, PLEASE ACCEPT OUR THANKS AND DISREGARD THIS REQUEST.