[Guardian]

That's a very good point on steam sales. There are some where they practically give the games away. It's probably not profitable for the developer, but you don't see that quite so often on store shelves.

They don't make much of of it, but they do get some small residual income from them that isn't usually accounted for. A lot of games bought during that time would not be bought by the numbers they are if not for the sale.