With the launch of Zynga’s FishVille, I’ve been watching to see if the developer could again eclipse records for user growth. The last Zynga hit, Café World launched a little over a month ago, gaining 1.1 million new users on day two and an additional 1.4 million users on day three, eventually passing rival Playfish’s Restaurant City and reaching more than 5 million daily actives in just a week after launch. In its first week, the numbers for FishVille are strong: 1.6 million daily actives after five days, whereas top rival fish game, CrowdStar’s Happy Aquarium took more than two weeks to hit that level. But the growth is not quite as meteoric as Café World.

With all of Zynga’s promotional muscle and ability to cross-promote games across an even larger installed base of players than a month ago, what happened? Are users already mega-engaged with existing titles? Unlike Café World, FishVille is competing with three games and trying to tackle a much more established base: Happy Aquarium, TwoFishes Interactive’s My Fishbowl and TallTree Games’ Fish World collectively have 11.3 million daily active users and over 39.1 million monthly users. In aggregate, these games only trail Zynga’s FarmVille.

In addition, the launch was marred a bit. One of Zynga’s offer providers was running scammy offers, so Facebook took it offline for about 36 hours. With that caveat in mind, I decided to look at the launch trajectories of recent titles by Playfish and Zynga to see if we could discern any trends to benchmark the performance of FishVille:

Read more of the analysis on InsideSocialGames.com