Online advertising firm ValueClick said late Wednesday that it has named John Giuliani as its new President and CEO, replacing former CEO James R. Zarley. Zarley becomes Executive Chairman of ValueClick's board of directors. No reason for the change was given by the company, and ValueClick said there would be no change to either Mr. Giuliani's or Mr. Zarley's compensation as part of the move. Zarley served as CEO of valueClick from 1999 to May of 2007, chairman between May of 2007 to April 2010, and then back to CEO and President since April of 2010. Giuliani has been ValueClick's COO since April, and prior to that was at Dotomi.