I'm no Marketplace or Freebie expert, but I do believe that if it takes time that you consider valuable out of your life to make such a thing and you feel it has value that other's would invest in, then you should market it. If you did it out of love or it really took little "effort" or you deem it not worthy of getting some value from your efforts for it, then it should be a Freebie. That's just my unworthy take on the subject. Your mileage may vary according to other opinions stated here.