If you want to get something second hand or sell it, this is the best venue for accomplishing that. I've sold lots of things that I would have been inclined to throw out, but it seemed like somebody would want them, and they did. Not everything sells, but I'd estimate I've sold 80% of what I've listed. It's not like you're getting top dollar, but for a small effort, you're getting some $ and you're not filling up a landfill. I've bought things as well and gotten what I expected.
Personals are a whole other experience. I thought I was looking for a relationship, but I'm just finding scams for my credit card posing as Age Verification and safe "dating" sites... and hookers, yep hookers, ya read that right. I haven't put up an ad myself, but checking the "Women seeking Men" section, most posts are trying to steal your credit card numbers and some are simply soliciting. If you're looking for love, try elsewhere.