GameStop is not a competitor to Valve unless you consider 'sells products to customers' a single market. Their competitors are services like Direct2Drive, Impulse, Humble Store, etc.
If someone actually wants to go out and pick up a box, they're not going to do that on Steam.
It's true that digital distribution in general offers lower costs than brick & mortar, but that's not specific to Valve. At most they were leading the charge on digital distribution with Steam, but even when they did that they were still selling copies at retail.
If someone actually wants to go out and pick up a box, they're not going to do that on Steam.
It's true that digital distribution in general offers lower costs than brick & mortar, but that's not specific to Valve. At most they were leading the charge on digital distribution with Steam, but even when they did that they were still selling copies at retail.