EXHIBIT 23.1 CONSENT OF INDEPENDENT ACCOUNTANTS We hereby consent to the incorporation by reference in the Registration Statement on Form S-8 (No. 333-90653) of DoubleClick Inc. of our report dated June 20, 2001 relating to the financial statements of the DoubleClick Inc. 1999 Employee Stock Purchase Plan, which appears in this Form 11-K. PricewaterhouseCoopers LLP New York, New York June 27, 2001