Honestly, I find the subject matter of the ad more relevant than the presence of an ad. Partner up with good sites like New Egg or Tiger Direct for ads and you're bound to get some good numbers. Stick with Google AdSense (and that's not to say anything negative about AdSense) and you wont see near the same numbers mostly because

1. Everyone recognizes AdSense and it doesn't really stand apart from content (this reflects on how effectively and tactfully place your ad)

2. More common is it becoming to see Ads on AdSense that point to TLD's that display no relevant information, or useful data, so people automously ignore them.

Advertisements are all about the audience, much less the product. Get the right ads, and you'll see results even with the techie crowd who are more familiar with blatantly bad advertisements.