although this may look simple for me it's one of the best ideas here for a giveaway. Literally all you have to do is something that should consider a must thing, commenting on people's posts that you like. You are both rewarding the interaction and boosting it! 

Also the way the giveaway is based is pretty cool. Depending on your comments you make you take a portion of sbd/steem whatever, once again leading people into making more comments and interact more. Hopefully this will lead them to do it to other's post not just for the sake of some rewards :P but it's something anyone can do and there no restrictions that i have seen in other giveaways like resteems,have rep lvl below or under "insert number" etc etc