A few years ago, I signed up with Amazon Associates. This is a service of Amazon, where you can put links into your articles to Amazon products
Say your article is something about Obama, you could link to his biography on Amazon. When a reader clicks through the link, and buys something off Amazon because of your link, you will get a percentage of the sale.
Even if the reader does not buy the exact item to which you’ve linked them, you still get a percentage of whatever they buy.
My articles link mostly to books, movies and music, so it’s surprising that sometimes I get odd sales through Amazon. Here’s a list of some of the odd things which people have bought after coming from my site CountyHistorian.com