I once defined in steemit.chat what would b an thical contest:

• No upvoting required
• No following required
• No resteeming required

I think your contests, which are awesome giveaways btw, fall under that.

Worst contest/competitions I've seen on Steem are those with a minimum upvote requirement. Say "Prize will only be awarded if post reaches $70".

So, basically, you get some dolphins or orcas to downvote so post only ever hits $65 and you bank it all, flipping the bird on everyone?