Are your female OCs more than Pinkie Pie/Fluttershy/Twilight knockoffs? Is your OC more than a bland, one-dimensional loser the average (Well, below-average) reader can identify with? Are your male OCs more than Sokka/Kirito/Spike knockoffs?
Does your OC have hopes, fears, dreams, a job, and a spine?
Is your OC an actual original character?
Then sign right up, and join a community that knows what "OC" stands for.