I read an article where a fan of the game suggested that you guys could sell buddy slots in the in game store for PokéCoins. That would be kind of cool. Also, I think it would be interesting if a buddy Pokémon could pick up 5 to 10 candy for however many kilometers walked instead of one. The greater output would increase our chances of evolving rare Pokémon
Number Eleven about Pokémon GO, v1.39.0