i think the lesson is this: the more tech-oriented your target crowd becomes, the more you need to base your revenue model on sponsorships. the masses will click. the web veteran won't click but will view PPM ads. the tech-savvy will adblock all standard ads.
It's an interesting insight into the business models of many Web 2.0 startups- your early beta users will most likely be tech savvy, and thus the least likely to click on your ads. In other words, don't expect to make money from AdSense anytime soon.
