[g00dn3ss]

As another poster mentioned - guess what happens when you try to block things and the blocking becomes common. Think spam or popups. If there are financial incentives, the advertisers getting blocked will just get more creative. Its the usual arms race. Text ads just haven't gotten annoying enough for most people to block.

I do think Google's advertising model can't last forever. Just like the old "pay per view" model mostly died out on the web, the "pay per click" model will die out too. The obvious next step is pay per sale. Yes, it's hard and has problems. But if somebody finds a good way to make this work, this could potential steal away some of Google's business.