My primary business is eBay, I have a store and sell mostly used clothing and make ok money at it. Enough so I don't have to go get a job and can be home with my kids. For the past year or so I have been dabbling in article writing for these two websites and it is all starting to pay off. not alot but consistently and the more I write the more I make over time.
The key to both is to write like articles and link them together, share them on social websites like facebook and twitter. Add to the articles and republish often to keep them fresh int he search engines and MONETIZE them with google adsense, cafepress, amazon, clickbank (not allowed on hubpages), and other affiliate sites.
The idea here is to give relevant information about the subject and ad the affiliate stuff as additional options for your readers. This way you are not looking all addy and your reader will trust you enough to click on the options for more. You can see an example of this on my article about saddleing horses. http://mepperly.hubpages.com/hub/How-to-Tie-an-Off-Billet Although there is not a lot of advertising on this article because hubpages limits the advertising there are things to click on that I will get kickbacks on... enough of these articles and the money starts adding up.