On my image sharing site I have a prominent facebook login option and only about 1/10 users use it to login, the rest create an account normally. I'd recommend

On my image sharing site I have a prominent facebook login option and only about 1/10 users use it to login, the rest create an account normally. I'd recommend having both options. Of course, users may be less inclined to login with facebook on a site like mine, where they are sharing content that they may want to keep separate from their facebook identity.