Actually, they aren't going to 'wise-up'. The cost for putting the ads up there is pretty small. If only one tenth of one percent are legitimate interests, that justifies the trivial cost.

However, one thing you would have to consider is this: Ad revenue is paying for all kinds of things, such as Google, and this particular site. If there was no ad revenue, what else would be keeping the lights on? My annual fees for this site wouldn't even buy a cup of gas for Brad Jones's Ferrari Testosteroneosa, let alone pay for the servers. If our annual fees aren't going to pay for the site, then who will? Right now, it's ad revenue. If that goes away, then, unless VBF can get a government grant (and therefore be paid for by taxpayers, which isn't going to happen), then VBF will, itself, go away.

Frankly, the internet can appear free because people are finding ways to make money around the edges rather than charging for it directly. If that model changed, it would rock the world.