Can you draw me a grinning face with X's for eyes and a top-hat. I won't pay you anything but i'm a very prominent and up-and-coming mafia player who will use the avatar to accrue multiple mafia trophies and people will wonder what's the avatar about and I'll link them to your tumblr.
Think of it as a proper sponsorship. You don't stick your logo on your mom's van. You want the sportiest fastest car in the highway and right now that's me. I'm meaner than a 3-year old without morals who just had their toy taken away.