They are discounting professional equipment and concentrating only on gaming. 

I know people that bought ps3's and xbox 360's and use them almost exclusively as media hubs / cheap hd-dvd/bluray players, doesn't mean it wasnt a console sale, and doesn't mean the money paid for the console is any different, intent changes nothing when comparing the cold hard sales data.

If you sell 100 consoles and 100 graphics cards, does what people chose to do with them change anything?

Yeah, this is only a measure of PCs and upgrade hardware sales. It does not explore actual use of said hardware. So while it is true that the PC hardware market is vastly huge than console hardware it does not necessarily follow that PC gaming is vastly greater, or even equal to, the console market.

I have a pretty low power laptop I use to play Smite as the only gaming application. But its primary purpose is for watching movies and TV shows streaming on my TV and for surfing the net. But if my country was covered by this survey then my laptop purchase would be counted.

So all in all not really a good method for trying to measure the size of the respective gaming markets. I suspect mobile phones as gaming devices blows both of the traditional gaming platforms out of the water, so perhaps developers should be optimising for mobile phones because so many people buy phones capable of playing games.

You know, it mentions that $17 billion come purely from the performance/enthusiast crowd, which is still more than the consoles. 74% were either performance or enthusiast sales.

well, many PC gamers spend their money in MMOs, F2P games (the irony) or indie games (that market should be much much bigger on PC). Then we have games like Diablo which sell better on PC, games like Football Manager which are only on PC and sell pretty good and games like Borderlands or Skyrim which should do really good on PC. 

Games market  is just different on PC but surely not smaller.

And almost all sales on PC are digital so that we have to be lucky to even get numbers from devs. 

Are they counting every PC sold on the market lol? If so they those aren't all gaming PCs.

What is performance/enthusiast? How would they know what the primary use for that $17bn is? They are looking at sales of PCs/Laptops that have mid-level and higher GPU/CPU/RAM(?) set up and sales of stand alone GPUs CPUs RAM etc (for building / upgrading hardware). But my work laptop has mid-level specs and would have been regarded as a "performance" laptop at the time it was purchased. But it ain't never been used for gaming. There are a great many uses for "performance" PCs that have nothing to do with gaming, yet all those sales are being counted in the $17bn.

The only reliable stats you can get to indicate gaming enthusiast user base on PCs is the number of unique individuals that have Steam, Origin, battle.net etc accounts, and some sort of statistical analysis of disc based PC game sales.

Someone upthread reckons 70 million Steam accounts. If the PC upgrade cycle is 4-5 years as the PC crowd here say then the hardware sales for Steam account holders amounts to approx 14-17 million users buying new hardware per year.  Combined console sales for 2013 (a down year because of the generation transition) excluding hand helds was about 28 million. So if Steam users represent half of all PC gamers that means the number of gamers who purchased new PC hardware (whether a whole PC or bits for upgrading) would amount to 34 million users. That's nothing close to double home console sales, and is less than console sales if you add in handhelds. And I think 70 million PC gamers who are not on Steam is probably on the high side.  Who here on VGC is primarily a PC gamer who doesn't have a Steam account?

Bla bla a lot of people use their consoles primarily for media too or as dust collectors.

And there are a great many consoles out there that are being used primarily as bluray players or Netflix machines. What's your point?

The primary function of dedicated graphics is marketed towards gaming, just like the primary function of consoles is marketed towards gaming. Are you going to count out all console sales because some may not game on them (tons of people use the PS3/360 as cheap bluray/DVD/Hulu/Netflix)?

And console generations aren't much longer on average. PC upgrades come 4-6 years, console generations are 6-7 years on average. Not to mention. that only small parts of the PC are upgraded, not the entire thing.