Steam

It's also an indefinite cost. It's not like Valve decides to stop hosting a game they've sold after a while. Generally speaking, they store and host it forever even if they never get revenue from sales of it ever again. Of course, I'm sure if the revenue wanes that much that downloads will too, but there's definitely a crossover point where maintenance will start being a permanent negative cashflow. Now multiply that across tens to hundreds of thousands of games and counting. Forever. You kind of have to consider that for the long term when setting your pricing for today since sales cuts are the only revenue you get.