A combination of writing online content and affiliate marketing. People should build their writing skills and learn the ins and outs of writing online and then add in affiliate marketing stuff, like Amazon.
If you are seriously looking for a way to make money online then you have to be patient, especially if you use places like Hubpages to write. It doesn't come over night, but it does add up.
There are tons of writing opportunities online for up front pay and revenue share.