It would certainly be interesting to understand if it's a functional long tail. For me personally, I often end up picking up games on sale or in Humble Sales (

It would certainly be interesting to understand if it's a functional long tail. For me personally, I often end up picking up games on sale or in Humble Sales (which have Steam keys) because my two gaming PCs are ancient by modern standards, so I'm generally buying games which are a few years old to run on them. The former point may well factor into Valve's thinking; they have very good information on people's hardware, after all.