Giveaways are allowable, just be explicit of the rules...very explicit. Include things like:

• Who wins, based on what?
• Who chooses?
• What is the prize? (pair of steemit shoes)
  • Is it a specific size? If not, how do you want to communicate the winners shoe size? What address to ship it to? (have them either leave a comment with it or direct message you in steemit.chat or discord)

I know this is a bit overboard of a breakdown, and you don't have to do all this. It's just how I ran giveaways, contests, etc ...be as straight up as possible. :)