Welcome to Domain Social, a domain forum where people sell domains and buy domains, talk about domain name registration and help others when buying and selling domains.
I have not done anything with Yahoo, but I heard that is not exactly easy to get out of it when you want. Apparently they are not exactly friendly when you try to sell something or move something out from there.
I have seen it but for some reason have opted to just stay away from it. It wouldn't suprise in the least if it was hard to get out of once you signed on.