How do people make money on line?

I have been looking for ways people can make any money on line and I have found that many of them confess that they make money on line:

* Reading Emails
* Subscribing to paid surveys
* Using affiliate programs
* Selling their own products
* Selling products of others

In fact, those people create sales pages sharing their secrets about how to make the internet a source of wealth.

But I have learned so far that experts and great internet and affiliate marketers focus mainly on giving excellent content, and making recommendations about excellent products on line.