Why prohibit giveaways? I don't think the giveaway threads should be considered spammy as users posts their bitcoin addresses to get tipped and some giveaway threads have discussions going on as well like Stunna's threads. That way even Auction and Lending sections have users just posting the template for loans/bids. It makes these sections also similar.
Infact,giveaway's are the most spammy threads that should be taken care of.Have you seen 777COINS giveaway threads? Its the home for Potential Activity hunters.Literally have a look at it.What does give away posts usually have apart from a random digit and a bitcoin address/username ? Not constructive at all.Multiple accounts are made just to participate in the giveaway's with different address.I could talk more but this is just enough.