-snipped, on account of my post's length-
Dude, my point is that the awareness / exposure you're talking about does not exist. Fighting games do not generate fans on any tangible level. They can increase awareness and maybe it does entice a few (and I mean, a scant few) to do a little research, but we're not talking about an attach rate that matters to anyone. They're not shifting book sales #s, they're not even swaying twitter trends, we're not even talking new facebook fan pages. Now compare that to the instant cathartis of including a character people actual know.
And this isn't even about $s. You think the Marvel playing community has any idea know who half of the MvC3 characters actually are or they're just celebrating their memories of previous games, saturday morning cartoons, and big budget movies? How many people shouting BIONIC ARM! know its made of 100% Grade A Ground Wife? How many know who Sam Alexander is or what character in the game debuted as a Captain America foe? 95% of the time, the right answer will come from someone who already knew before the game came out.
So who, in any arena, would bank everything that goes into making a fighting game character on a 5% play? Even if we bump it to 15%, no, lets say 25% of the people who buy and play fighting games bother to look into the characters. You're telling me this fictional marketing illuminati should play up a 25%
chance of developing interest in a little character over the 100%
certainty that players have already heard of a big character? You, in particular, have spent the entire campaign of this games development declaring what would be the best picks for this games exposure and development, yet here we are, at 25% Batman on all fronts and a hugely successful launch. The Manhunter and Cold armies did not rise to strike NRS down, and Killer Frost / Harley are getting more play than Wonder Woman.
This is why the whole "deserves it, requires it, demands it" theory of casting is worthless. It inflates the value of a character pick way beyond its merits. Nobody at DC or Marvel is dumb enough to think they're gonna build a fanbase from a character in a fighting game. Look at comixology. The Injustice Book is in the top 10 because its hot, but did anyone else climb up there as a result of being featured in the game? Are Nightwing or Green Arrow's numbers up all of a sudden since April 16th? Please send me a link to all that Hawkgirl fanfiction and DeviantArt that was inspired by her inclusion.
tl;dr, this entire casting circle jerk is about pleasing existing fans, not building new ones. Freddy proved it. Freddy (released last) is the most bought, most rated, and most played of the MK9 DLC characters by a huge margin, while Scarlet (released first) is absolutely on the bottom.