I'm getting an inkling that the reason why I am apparently in a vocal minority on these forums for my love of Steam is because I have a very solid wireless internet connection that I have not had any major problems with for the past couple of years.
And I'm not kidding about the millions part. Steam's concurrent users varies between 2.4 million at the low end and 4.5 at its peak, cycling every day. I couldn't even guess at how many unique users are on Steam in a given month, nor how many are perpetually in offline mode and so don't get counted.