Major companies are going to want the cosplayer to attend conventions, use their fan base to attract new customers to their product, do YouTube videos, posters etc.
As someone who IS the sponsor of a cosplayer (Zombie Bit Me) here on DA I wanted the cosplayer to work with me to create a character for a Pathfinder and Dungeons and Dragons Campaign Setting I was working on. We created the half darkelf character Cyrign for Blackbyrne Publishing. Personally I don’t want the cosplayer to be sending spam most major companies know sending spam posts even pictures of attractive cosplayers only gets your company message shut off.
I did this post of very little sleep so forgive the spelling and grammar.