So what does that mean? Well, I can have three of these on a page.
That is one, here is a second:
And the last, but not the least.
These link units are different from Google's normal AdSense units. If you click on them, they will take you to a page of ads, as opposed to an advertisers site. In a sense, two clicks are required to reach an advertisers site.
Forum discussion at WebmasterWorld.