so while the way ipquarx put it was super rude, he isn't really wrong.
rather than repeat what others have said about badspot being very anti-key sharing, here's a different note:
it's kind of silly to give away a copy of Blockland when you already need to own Blockland in order to be in the competition. some people who are great builders don't need another copy of Blockland, while others are people who need another Blockland key but aren't building-oriented.
also, offering a spot in your clan isn't a reward in all peoples' eyes. some people may find that to be a nuisance rather than a gift, you may even be driving away some potential builders.
if it's true that your
dad literally makes that in 10 minutes
then a fairly standard prize for competitions is to give the winner a $20 or under game of their choice, usually through Steam. it's quick and easy. i would recommend it, and you'd avoid all this trouble about blockland keys, but it's up to you.