Some people are so eager to anoint Infamous PS4's champion to go up against Titanfall. That's like Troy sending Hector to battle Achilles, but they chopped off one of Hector's hands first. The marketing for Titanfall is insane! I'm confident the Xbone version alone is going to absolutely smash Infamous in next month's NPD, and dare I say it will even outsell it worldwide. PS4 may be dominating in worldwide sales, but I don't think it will be enough to overcome Titanfall's monstrous tie ratio. Infamous is just not being positioned to be that sort of absolutely-must-have title for PS4. And that's okay. PS4 is selling well enough without needing to spend tens or hundreds of millions marketing any single title.
Regarding talk about potential lost PS3/PS4 sales of Titanfall EA incurred by selling-out to Microsoft, I have no idea what those companies' internal math says. It may have sold more simply by being available to a larger installed base. But I don't think it would have been that much more. First of all, if it was multiplat, Microsoft wouldn't be putting all that marketing money behind it. It would just be another multiplat FPS that goes up against COD, BF, KZ, etc.. It may sell well on its own merits after people experience it for themselves and sell it to their friends on it, but it wouldn't have that pre-launch frenzy it enjoyed as a hyper-marketed exclusive. I also think the 80+ million installed base of PS3 doesn't mean much. I think Titanfall PS4 would have actually outsold the PS3 version. I would have expected it to absolutely flop on PS3. Poor sales of late gen PS3 titles, even GT6, have shown that many gamers have moved on. I don't think an online-only multiplayer FPS that would have almost assuredly been the worst-performing version of the game would have sold well on PS3.