Ingsoc85: Hmmm... I imagine most of those are console sales.
shmerl: May be, they didn't break them per platform. I'm not sure why they are so stuck in using retail sales still. Unless it's a chilling effect of DRM (like some would prefer to buy video disks, since they actually can tangibly back them up, unlike all the digital DRMed video sales).
Buying console games through download is actually more expensive than buying the hard-copy version. The main exception to this rule is when there's a sale going on. For example, the retail version of
Destiny The Taken King Legendary Edition costs around $63 on Amazon (UK) but around $77 through the PlayStation Store.
Wolfenstein The Old Blood costs $24 in the Xbox store but $15 in retail.
Madden NFL 25, released in 2013, costs $83 as a download for the Xbox 360 but only $24 as a hard-copy.
Metal Gear Rising: Revengeance costs $18 in the PlayStation Store but only $8 or so in retail. And so on. By the way, the retail prices I've quoted refers to new copies, not used games.
Buying a hard-copy also reduces risk in that you can always re-sell your game in case you did not like it, so you can recover some of the money spent on the game. Being able to re-sell the game once finished serves the same function. When you buy a game digitally, by which I mean 'not hard-copy', you can't counter these risks.
Impulse buying is also a factor, if you happen to be in a retail store and spot a game you want its quite easy to end up buying it because the nature of holding a physical product makes it more enticing to own.
As someone who needs to have a tangible backup, which I have of all my GOG games as well by the way, buying a hard-copy of a AAA title is a better option than buying through Steam. I re-bought
Project Cars on console for this very reason, despite already owning it on Steam. I will most likely do the same with
Assetto Corsa and
Dirt Rally as they eventually get released on console. I do the same with PC games, I recently re-bought
Euro Truck Simulator 2 on CD after learning it doesn't require Steam and I've re-bought my favourite games on Steam on GOG.