Sony didn't have "game after game" with ps3 unless it is 2009 and 2011 you're talking about. And none of their games sold more than Gears series or Halo Series.
It added more variety to their lineup and probably pushed more sales.
If you take all the ps3 exclusives from those years and combine it, the best possibility will equal Halo 3, Halo Reach or Halo 4 indvidually.Also, remember people who bought Uncharted 2 might've bought Killzone 2 so even the combine sales won't add up to what an indvidual Halo title sales. Let alone, gears, forza, fable and more coming out in the future. In terms of block buster exclusives, Microsoft has Sony beaten. The only big titles from Sony are Naughty dog games like uncharted and the last of us and maybe GT (unless GT6 is a sign of things to come).