The central contention I would make, and which I think Gorbles is making, is that the BE launch was comparatively much smoother than the Civ5 launch. Player retention is largely irrelevant to that contention. Retention rates are a function of how many people enjoy the game, once you get past any technical issues and game-breaking bugs that plague the game upon its launch. But if 80% of Civ5 players upon launch absolutely loved the game, and 20% of them couldn't get past turn 5 because of constant crashes, then that launch could be said to be less smooth than the launch of BE, if only 20% of players absolutely loved the game, but only 2% of them were facing game-breaking technical issues, I don't think there's much dispute that, when you put aside the technical issues, Civ5 turned into a more successful game than BE. Civ5 vanilla faced huge criticism that was unparalleled with BE, but that's probably because of a larger total player base, and because of the initial technical issues. Overall, it was clearly a more popular game than BE, and that was capitalised on with G&K in a way which hasn't really been done with BERT. But the launch itself was clearly more problematic. It's hard to pick a metric for demonstrating this. I'm basing it on anecdotal evidence, having been a keen observer of both launches. Perhaps the number of bug reports and tech support threads might give an indication. But player retention rates do not.