This path is the most downtrodden, but very few people explore all the potential to make money, even here. That's because most people are creatures of habit. They find one way to do something, and they never venture from that path, even when they find that the income isn't what they had hoped it would be. The fact is that if you limit yourself to just one advertiser, like Google, you won't be able to really explore the potential for affiliate marketing models that might work better with your niche audience.
So, while we are going to tell you that you can make money using Google Adsense, it's not the only advertising network out there. You can spend a lot of time trying to publish content that gets search engines to serve up high-prized ads on your site, and researching keywords to make campaigns that target high-paying ones. Or you can explore a few other places like Adbrite.com or independent affiliates at different affiliate banks who might give you a bigger return on your investment of time.
The key is not to join the biggest network out there, it's to understand your niche and your audience. To make money as a publisher of other people's affiliate offerings, your job is to match up your audiences wants and needs to the offerings that best meet them. So, you don't necessarily have to know a thing about keywords to get started being a publisher of affiliate offerings, but you do have to know what your audience will buy.