My main source is MY life!!! I spent most of my adult life experiencing anything that wasn’t too dangerous or illegal. In the process, I’ve learned a LOT of things the HARD way which, in my opinion, is the ONLY way to learn!!! I’m a member of one site where I earn points for various activities & doing a Search earns me points. On top of the points thingy, they use a combination of Google, Yahoo, & Bing for the results; so, by doing my one search, I get the benefit of the top classified results from all 3 of the major search engines. I find it to be much more efficient than just using ONLY one of the search engines!!!