People in my family have also used craigslist pretty extensively for housing -- finding rentals, looking for real estate, etc. Help wanted ads are sometimes very good leads. It even has discussion sections on various topics. Here in Maine, we have a great little publication called "Uncle Henry's," which is now online as well as in print. It comes out once week in print, and is cram full of all kinds of stuff to sell and trade, including even farm animals and such. I once managed to get rid of an old one-horse sleigh that a renter had left in the garage at my parents' cottage, and never retrieved, by advertising it on both craigslist and Uncle Henry's.
I do think you can sometimes make more money by going online than by doing a yard sale, and you don't have to put up with the bother of standing around in the hot sun,haggling, dealing with unwanted "early birds," etc.
Small TA Grade 1, May-06; recur (2 tiny), same, June-08; TURBTs both times. BCG begun July-08, dosage to 1/3rd May-10, completed treatment December-11. All clear since 2008.