Since the end of the primaries, Democrat Barack Obama and Republican John McCain have run more television commercials in Philadelphia than in any other media market in the country.

And they have spent more money on ads in Pennsylvania than in any other state.

Those findings, which underline the area's importance in the election, come from the University of Wisconsin Advertising Project, which monitors political advertising in conjunction with TNS Media Intelligence/CMAG.

Commercials for the two major-party presidential candidates appeared 3,311 times on Philadelphia television from June 3 to last Saturday. Next on the list was Detroit at 2,870, followed by Cleveland; Grand Rapids, Mich.; Cincinnati; and Harrisburg.

In terms of money, the two candidates - along with the Republican National Committee - spent $10,319,000 in Pennsylvania, nearly $4 million more than in Ohio, which was second. Rounding out the top five were Michigan, Florida and Virginia.

Counting ads bought by his party, McCain has outspent Obama in Pennsylvania by about 3-2, a sign of the importance the GOP puts in trying to turn the state from blue to red. McCain has spent far more in Pennsylvania than in any other state.

Pennsylvania ranks second for Obama in spending, trailing only Florida, which he hopes to turn from red to blue.

In all, Obama has spent about $27 million on television and McCain $21 million in the last eight weeks.

Political scientist Ken Goldstein, who runs the project, said the results showed that the candidates were focusing on traditional battlegrounds - including Pennsylvania, Michigan and Ohio - despite all the talk about expanding the playing field this year.