yes, you have reason, i have to give my ideas first
When we talk about earning money from the net, we mean heer the e commerce which gave a good canal for the marketing including the b2b(business to business), b2c(business to consumer),c2c (consumer to consumer,b2e(business to employee) and the b2g(business to government).
But the e commerce is very large and the ways to earn money from it is very multiple because it depend on your activity ,saling(books,cd,dvd,vod,pc,tourism,colthes,online supermarket,renting...ect) and adertising.
a good and simple exemple to earn money by adevertising from the net
Google has launched the google AdSense it very interesting for people who have a web site, it means:
After subscribing with google AdSens you receive many advertisement corresponding on the contens of your web site ,you will earn money after each snip on the advertisement (more information on google.com/adsense).
This is a brainstorming however Any new ideas are very good for the dicussion.
Thanks