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Exhibit 23.1

CONSENT OF ERNST & YOUNG LLP, INDEPENDENT REGISTERED PUBLIC
ACCOUNTING FIRM

        We consent to the reference to our firm under the caption "Experts" and to the use of our report dated January 28, 2005, (except Note 15, as to which date is March 29, 2005) in the Registration Statement (Form S-1 No. 333-121528) and related Prospectus of Fastclick, Inc. for the registration of shares of its common stock.

	/s/ ERNST & YOUNG LLP
Los Angeles, CA March 29, 2005

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CONSENT OF ERNST & YOUNG LLP, INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM