Kate Kaye at Clickz has done some in-depth analysis of the online ad spending of Democrat Presidential Candidate Barack Obama. The Illinois Senator has spent $3.47 million this year in online advertising.
Of that, $2.8 million went to Google while Yahoo received $180,000. Smaller amounts also went to Facebook, CNN.com, Gothamist, and Politico.
Google, of course, dominates the online advertising market, so it's a smart play by anyone to spend with them. But Google just happens to be number 13 on OpenSecrets.org list of top donors. The list compiles monies donated by corporate political action committees and individuals (who must report who they work for when contributing).