The question is, what you want to achieve. Do you want to support the community? Do you want to build up your HP? Which player base would you like to pay attention?
I for myself like the chance on big wins, but dont habe the time to write loooong comments, everyday.
I may be inclined to put a bit of effort in a post to win a gopd price like the MuTerra Tamer Name / Tamer background challenge.
But this are challenges and nit giveaways.
Giveaways in my oppinion should be simple and fast to be done. But it is not possible to earn with them in the long run. Its support of smaller players.