I have compiled sales data for each title of the main First Person Shooter franchises to see how the genre is trending so far.

These are the combined sales for all consoles for each title:

Call of Duty: The franchise is trending down, Black Ops III kind of reversed the long decrease in sales started 6 years ago but Infinite Warfare sales reconfirmed the trend as it might not even reach World at War sales.

Battlefield: While the franchise is still decreasing in sales, it is now competetive against CoD. B1 is actually at 11.59M vs. 11.55M for CoD: IW. This is the first time a Battlefield game outsells a Call of Duty.

Halo: Since Halo 3, the franchise is also decreasing in sales. Halo 5 (4.71M so far) did not even managed to sell half of what Halo 4 did (9.81M).

Far Cry: This is definitely the healthiest FPS franchise and the only one whom its last release performed better than its previous iterations.

Killzone: While underperforming compared to the other franchises, Killzone games are quite stable, selling between 2.5M and 3M during the last 8 years or so.

Resistance: The franchise started really well in 2006 but did not manage to grow and finally died with really low numbers in 2011.

Overall we can say that FPS games are not doing so well. Sure, CoD and Battlefield are still doing great numbers in comparison to other genres but it seems the golden age for that genre is now something of the past.

CoD IW outsold BF1 by a large margin.....how is it higher?

Overwatch has done very well though...

Does this include digital?

I don't know if we can say "FPS games are not doing so well" with only a small sampling of titles. What about Overwatch or Doom? I think it would be more accurate to say particular franchises aren't doing as well. It's become a more crowded market-place.

Inifinite Warfare sold 7.15M (PS4) + 4.40M (X1) = 11.55M while Battelfield 1 sold 6.87M (PS4) + 4.72M (X1) = 11.59M.

Shame for Resistance. Was a better franchise than most of the rest.

Vgchartz figures dont include digital sales. Frank O Connor was stating 5 million shipped after the end of 2015 (which may or not have included digital). It certainly has sold better than 5 million at this point (if I would wager, I would say between 6 million and 7 million).

I posted on the other thread (must have been a repost by accident).

"with only a small sampling of titles"

Come on, I picked up the main 6 highest selling franchises of the last decade. Overwatch only has 1 title so we cannot call it a franchise yet. Same goes for Doom which saw a reboot in 2016 but did not release any new titles since 2005.

On console COD IW sold more but if you add in Console and PC BF1 outsold CoD IW.

You said, "Overall we can say that FPS games are not doing so well."  If you meant "established franchises" instead of "games" then that's fine but I can only reply to the words you've chosen.  Those few franchises do not represent the entirely of the genre by any means.  

And what about Borderlands?  I know Borderlands 2 has sold over 12 million copies.