Nikko is one of the most marketable players in the game, if the THE most. Gateway's sales will suffer as a result.
I think it's a really interesting situation. Gateway's owner, from what I understand, essentially raised Nikko. So his decision to leave was likely a very difficult one for him to make.
What's interesting to me is that Gateway allowed Nikko to throw pretty much any disc he wanted. They didn't even attempt to hide that his bag was filled with Innova/Discraft's discs.
So why change to Innova?
By doing so, he limits the discs he can use, and inevitably weakens his bag, (I'm not saying that a 100% Innova bag is a bad bag to have, but a mixed bag, hand picked tailored to your own game, is always going to be better.)
Could be a money issue. A Nikko signature disc from Innova will certainly sell better than a Nikko signature Gateway disc, just on the fact that Innova dominates the distribution channels, (do you see a lot of Elements and Illusions in Dick's Sporting Goods?"
More likely to me, however, is the psychological part of it. He goes from being essentially the sole, #1 athlete for a niche brand with poor marketing, poor quality control and crap mold designs, (again, only relative to Innova/Discraft, GDS makes some decent discs, but nothing compared to the big boys) to becoming one of the top athletes for the most recognizable brand in his sport.
I think it's interesting anyway.