> It costs me nothing to install both stores on my PC.

But you wouldn't bother unless you have a reason to. I put off buying games I wanted to for months because I'd've had to install a new store. No-one is going to install a store for nothing.

> I buy Alan Wake 2 on EGS, great, that doesn't make me any more likely to buy the next game I want there.

Now every time you launch Alan Wake 2 they get a chance to sell you another game. If you see a game you like, why wouldn't you buy it on EGS now that you've installed it and know it works? They've got your email address now and can send you recommendations or tell you when there's a sale on.

Sure, it's still going to be an uphill struggle. But if they can't get you to install the store then they can't even start.