It's especially true now that the big media players are finally waking up to affiliate marketing (NYTime buying WireCutter and SweetHome) and BestReviews (which was already an epic product review site in it's self due to the fact they built their own 10,000 sq ft testing lab) being acquired by Tronc (owns the LA Times and half a dozen more publications).
Now you’ve got many different options to start earning online. If you saw something that really interests you, try it out and learn more about it. If you’re really wanting to make a full-time income online, you need to be dedicated to learning how to do what you want to do. There are tons of free resources out there. You just have to search for them!