What are some ways to make money off of the internet?

I'm talking about stocks...maybe advertising. I know it's pointless to say this but I'm not interested in get rich quick stuff and I'm not buying any scams.. it's just a serious curious question as to how to make a few extra bucks...just ideas...no business propositions. I heard there is some kind of thing on yahoo where if you get people to click on your link you get like a penny or something... how does one go about setting something like that up? Thanks