One of those "This is why we can't have nice things" stories.
Steam holiday sale, big promo, earn achievements and get prizes...discounts or even entire games. Steam accounts are free, so whats to stop someone from making hundreds of accounts and gifting the items to himself? Ah, Valve thought of that. You can only earn the items if your account is legitimate and has at least one paid game on it. Smart thinking.
What they didn't think of was...the Humble Indie Bundle. People have been buying up hundreds of bundles for a penny each so they can then make a Steam account, add a "paid" game, and get the now nearly-free goodies.
HIB has now set a minimum payment of $1 on the bundle if you want Steam keys. But damn people, way to be dicks and abuse everything.