I've sold a few things, works well, best if item is picked up, I've only paid first and got delivery after once, worked ok, a friend recently got scammed that way.
The scammer agrees a price, person sends money then scammer blocks you and you don't receive anything.
To prevent scamming don't pay first, can do COD. Also asking for ID passport or thai ID will help, I doubt they will get many fake IDs as they have many fake Facebook profiles