yes, but my opinion is that ad placement is doing more harm than good. for the site's audience, I think it's a safe assumption that they are fairly web-savvy and able to detect ads without too much effort. As a google adsense block, it's a cost-per-click ad. You see where i'm going with this... savvy users, poor ad placement = very few clicks = no revenue.

of course, that is all anecdotal... I'd be really interested to see real performance numbers on it.