By NBC's Mark Murray and Adam Perez, on MSNBC's First Read

On First Read, we often discuss the size of TV ad buys. (Is it a $100,000 buy? A million-dollar buy?)

But the folks at Kantar Media's CMAG have determined which TV ads have aired the most so far in this presidential race. Here are the top five -- two of which are Democratic-sponsored ads for the general election, two of which are GOP primary ads, and one of which is from the Karl Rove-backed Crossroads GPS hitting President Obama.

5) With 4,387 airings, the Democratic National Committee's "14 Months" promoted President Obama's jobs plan, using clips of his Sept. 2011 jobs speech to Congress.

4) With 4,650 airings (and still going), the pro-Romney Super PAC Restore Our Future's "Values" hits Santorum for being a Washington insider and for voting for pork-barrel spending.

3) With 5,006 airings (and still going), the Romney campaign's "Moral Responsibility" is a positive ad, with Romney declaring that he'll cut spending and deficits.

2) With 5,057 airings, Crossroads GPS's "Shovel Ready" criticized Obama's economic record and the stimulus.

And, drum roll, please...

1) With 6,190 airings, the Obama campaign's "Unprecedented" rebutted a TV ad by the Koch Brothers'-backed Americans for Prosperity hitting the White House on Solyndra.

View the original MSNBC First Read Post online.