How can bitcoin sellers are protect from it?
If you are getting direct from them... it should be ok. But there is always risk as bitcoin is not reversible. I might suggest trying small amounts I was not horribly impressed when FAQ had a dead link which was suppose to be about what bitcoin is - https://gyft.com/what-is-bitcoin/ . So makes me wonder how much time they really put into it I personally would use a exchange myself.
If you are talking about getting gyft or any gift card from a 3rd party (not gyft). Yes it is very risky and many scams have happened.
Thanks for the response.
I'm planning to sell BTC for GYFT.com codes which, buyer is buying those codes directly from the Gyft.com and send me to exchange BTC. Is that still risky??