As @steevc already knows, I'm a bit sceptical of competitions. When I first joined there was very few, there was stuff like @minnowbooster and a couple of Lottery type offerings as well as services offering to upvote you for a couple of dollars. I took a break from Steemit for around four or five months and having come back, or at least notched up my activity a couple of gears I've noticed how every other post or three in row is a competition of one sort or another offering you payouts in return for your hard earned dollars. I was that depressed I wrote a post about it.

Personally, I just think there are some elements praying on the desperate with all these 'Games' I prefer services like @shadowbot who just ask to use your voting power and who in turn use the groups voting power to upvote you. It's always a danger when money is involved, it does tend to bring out the sharks.