I think "gamers" is an overstatement.

If that was true, PC software would outsell consoles by alot.

I wonder how many of those "PC gamers" have mid ranged and above builds like an HD 5770 or a GTX 460 ? 

That's a horrible metric. There are single games that have playerbases almost as big as that. For example League of Legends has 70 million accounts. Now a lot of them are dupes and inactive accounts but they also have 32 million unique players each month. Then there is World of Tanks that has 1.2 million peak simutanious players.  And that is just one game. If we look at the asian market there are games like CrossFire with 4 million simultanious players back in 2012. Steam is actually a small fraction of the global PC gaming market. It has almost no marketshare in Asia which is the biggest market for PC games (in terms of players and revenue).

See, I'd rather take the actions of game developers and publishers as a measure of how big PC gaming is, and if we look at the target platforms for a lot of big games released today (ie non indie games) then the overwhelming majority are targeting consoles. If you look at the earning reports of the major publishers such as Ubi, Activision, Take 2, the majority of their earnings come from consoles.

That would indicate that though I'm sure there are 711 million people that play farmville or solitaire, the majority of money paying gamers are on consoles, otherwise publishers would be seeing higher revenue from PC games than console games, and the PC platform would be the lead platform for most games.

You also need to keep in mind that intel has no presence in consoles (unlike its competitor), so its in their interest to promote and talk up PC gaming, just like nVidia.

I know people that have 3 steam accounts because they got banned on "X" game.... Also, not everyone uses steam, some people use just Origin, or Desura, or some don't use anything and play games like WoW or other games. Plus people who play browser games. They would technically be PC gamers.

I know people that play those facebook, chess, and card games on pc

Yep, and 650 million of them only play spider solitaire and Facebook games.

I, and my lab computers, are several hundred gamers! I never knew!

I have no doubt that gaming revenue on PC dwarfs that on gaming consoles.

It's just a hell of a lot more spread out over a vast array of genres and types.  MMOs, micro-transaction games, and casual titles make up a massive segment of that in addition to AAA multi-platform titles.  A friend's wife spends a lot more time gaming than anyone I know, and probably a lot more money, even though she only plays easy puzzle and mystery games.

We might not want to count these other types of games but people in the gaming industry certainly do.  Money is money.