They would have a lot of rules! Actually, if they ever intend to make any money from it, I can understand why they would.
But it certainly is an interesting gimmick... I'm not sure it's a *healthy* one but ... <shrug> To each his/her own. And really, though we don't say it, for those of us just starting out, we DO end up doing a lot of work for free - just to get out foot in the proverbial door.