I have 3-5 accounts and never downloaded a game

Then those accounts wouldn't be included in this total as they're not active. If the total number of accounts was included in this list it'd be huge.

3-5 accounts without ever downloading a game?

What about that doesn't sound kosher?

Maybe he has an obsession for collecting accounts.

Very practical 

The way things seem to be going, Steam looks to be as much a gaming platform as any console. Arguably they have one of the soundest business model as they only have to keep people coming back and buying from them and they don't have to worry about things like hardware generations because their customers figure that out for themselves.

I think Gabe Newell made this point a year or two ago. It's highly profitable for them as they've effectively got the userbase and community of any of the consoles but as you say none of the hardware costs. Furthermore, they receive a fee for being the platform holders and get more profit per sale on each of their first-party software as they're also effectively the retailer and have no packaging costs. And now they're now actually expanding the hardware they're on with Mac and cross platform play via Steamworks.

Valve must be rolling in money...

Erm, all of it?

Sounds like someone didn't read the definition of an active account in the OP and decided on a bit of trolling.

To be fair, most people i think just have steam log on when there computer does.

And to think they're a private company.  That means the owners could be rolling in dough if they want.