Until a few days ago my answer would have been "no", but just recently the Google AdSense team released an upgraded interface to the system that now lets you identify just what you seek, though it's sure not easy to find.

Let me show you how a recent day broke down for me. First step, log in to your AdSense account. Now instead of looking at the usual Overview report, click on the Advanced Reports subtab. Now you'll see this:

Now you'll want to choose AdSense for content on the dropdown, leave it to show Aggregate Data, choose a date range (I suggest just one day as the way it displays multiple days is pretty darn baffling in my opinion) and then make sure you specify that you want to show data by Individual Add Unit.

All of a sudden a new checkbox will appear: "Show data by targeting type - contextual or site":

Make sure that last checkbox is checked and click on Display Report.

Here's what you'll now see (albeit with different numbers!):

Please click to see full-size image

As you can see, I earned $229.89 in AdSense earnings yesterday, of which $221.40 was generated by contextual advertisements (that is, standard AdWords ad campaigns showing up on my AdSense pages) and $8.49 was generated by site advertisements (where advertisers have specifically targeted Ask Dave Taylor). The numbers do show that there are definitely one or more companies that are targeting my site but that their combined revenue doesn't, as Rick Blaine might have said at the Casablanca airport, "amount to a hill of beans" at this point.

You should be able to generate the same report to ascertain whether or not there are any advertisers targeting your site, and good luck to you!

While I'm writing notes in italics, let me also thank my pal Anne Mitchell of The Internet Patrol for bringing this cool new Google AdSense feature to my attention. Thanks, Anne!