Here's my solution:
Put out a patch including the dlc for the first 2 weeks so you can only get it if you go on the game (just like Tekken tag 2)
put it out on store for a price
this would also encourage more people to play as there already on the game. (a few times I've bought dlc and downloaded it but didn't play it for ages)
I am not an active forum member, but I have not seen anyone complain about people who do not own the game being able to download the DLC for free during the first two weeks.
Why would they be upset? I mean, it would encourage more people out there to buy the game. More sales are nothing but beneficial to both SuperBot and us, the players. If the game continues selling more copies, we’ll keep on getting more wishes granted with future DLC characters.
Those are just my $0.02.
Mains: Big Daddy, Sweet Tooth
Learning: Ratchet, Sir Daniel