Moreover, what percentage of the population is even aware that A) you can buy games to play on the computer, and B) that didn't come from a big box retailer? I'll tell you this -- it's very much in the minority, especially when you look at the 30-and-up crowd. Much older than that and the percentage of the population starts to approach zero.
I grew up with an Atari VCS 2600 (that my parents had bought for themselves), as did most others I know. However if I asked my parents -- or those of anyone I know -- what Steam was, they wouldn't think of anything other than water vapor. Humble Bundle? Not a chance.
I've heard of kids on the bus and subway recently, talking about "this new Steam thing". If kids aren't aware of it, how aware is the general population of something far more obscure? Not very.