Yeah, I would agree that the best way is to slowly build a network of
useful sites and optimize them for advertising. It's like running a brick and mortar business; you're selling a valuable service--the right to advertise to your visitors.
The bad news is that many others are selling that service as well, but the good news is that overhead is very low--hosting costs next to nothing and domains sometimes go for as little as $3 a year. Because of the high level of competition and the low overhead, the best strategy is to diversify--start a lot of diffferent sites focusing on lost of different audiences. If one of your sites take off, you'll have an income stream. If a few of them do, you stand to make a lot of money.
Either way, it takes time. As many people have already reiterated, get rich quick schemes work about as often online as they do in the real world. However, there is money to be made if you're willing to put in the time. And of course, failing that, there's always the poker option
Tom