I agree, even if it’s just 1%, it’s still a lot of people. But at some point in the future it will probably start declining, as more of these people get used to the Internet and develop a good idea of how things work on the net. When you’re a new user and you get spam emails, it is easy to believe those emails, you just don’t know any better. After a few times of being fooled by them, unless someone warns you, you start to learn about them and be more cautious.

Online advertising is also being attacked from another angle right now: click fraud. As an advertiser, that’s a big problem for you, because it undermines the reliability of online advertising. You start to wonder if every click you pay for was worth it. It will get really interesting once someone releases a virus which just sits on a PC distributing itself, and downloading content from various websites and randomly clicking on the Google ads, for example. You could have a new generation of spammers, who just set up random sites everywhere with Google ads, and have those bots click on the ads from various PCs around the world, pretending to be real visitors. That way the spammers get paid more often, the advertisers get more hits and have to pay more money, but they are left wondering where the ROI is.

At that time, Google is going to want to buy/invest in/or work together with an Antivirus/Antispyware company and have the technology integrated in their Toolbar for example, to try and fight the problem. I don’t think those websites that protect against click-fraud right now are going to be able to effectively fight the problem. And then it’s going to be a continuous fight again, similar to spam and spamfilters.