Placing ads on a site

[johnny_d]

I've looked at the code of the first vertical banner ad on the main page of sex.com, and it looks something like this:

<iframe src="http://delivery.ipvertising.com/afr.php?zoneid=35&amp;cb=87971" frameborder="0" scrolling="no" width="160" height="600"></iframe>

I've seen a lot of xxx websites (especially the big / high traffic ones) doing something like this, using different ulr for the ads.

Do you know / can you tell me how this works?

Thank you.

[johnny_d]

Is it possible to track number of clicks, are where they are coming from (number of clicks per referring domain would be the best; the more info the better) with something like this too?