Then you start jamming affiliate links in places so you get a percentage. Then you target more and more keywords that are convertable. Then you have a newslette

Then you start jamming affiliate links in places so you get a percentage. Then you target more and more keywords that are convertable. Then you have a newsletter that pushes those products. Then you take money to write articles/reviews/videos about some product. It's not just jamming banner ads everywhere, there's a lot you can do to increase revenue with advertising and referrals.