When I am talking about market fragmentation, I was referring to the electronic distribution market: I mean that a distribution platform that has a lesser offer but has exclusive (permanent one) because of a tied up with a specific publisher is very restrictive. I wouldn't have problem if, in this case, Valve and EA could agree to allow reselling of title through their respective distribution system.

Imaging that, going to your local super market (ASDA for an example) you could not find a major brand of cereals (Kellogs for the sake of argumentation). And that you would have to go to a direct competitor to find it (Tesco in this case). This is a fairly strait forward hurdle against a free market.