From ClickZ…

Barack Obama’s campaign spent at least $3.47 million on online advertising related purchases between January and April. The biggest recipient of the Democratic Presidential hopeful’s online ad dollars was Google.

The search giant scored over 82 percent of money spent on online media buys for the Illinois Senator’s campaign this year through April, according to information compiled from Federal Election Commission filings. More than $2.8 million was paid to Google, as listed by Obama for America in its itemized FEC reports.

After spending about $640,000 in January on online advertising, the campaign pumped its online ad budget up to over $1.9 million in February. Expenditures tapered to about $888,000 the following Month. Filings show spending of only around $234,000 in April. However, previous monthly reports suggest more April online ad payments will be reported in the future; Google didn’t even appear in April spending data supplied by the campaign…