One explanation would be that the people who you "scammed" into viewing the site, turned up and didn't find the content they expected, so they went and found so

One explanation would be that the people who you "scammed" into viewing the site, turned up and didn't find the content they expected, so they went and found something else to click on - i.e. your Adsense. Good old bait and switch. I don't know if it particularly invalidates Adsense as a business model (if we're calling it that). Lots of forms of subterfuge or gaming of click-through advertising systems can increase your earnings. It doesn't mean that people who garner legitimate revenue can't do well (although presumably they do have to pay for the cost of the people using the system illegitimately). However, I've always found Adsense totally useless for the sites I run. I have a niche, high-tech audience, so Adsense CTR are ridiculously low for me - particularly compared to what I can get selling CPM rates to advertisers directly. Again, that doesn't really invalidate Adsense as a whole - just that it isn't suitable for everyone.