No it's not. Look at the appdata traffic http://www.appdata.com/apps/facebook/155727011143809-i-am-pl...
Around 150k daily active user, it's nice, especially for a first game, but with that you are not even in the top 300 of the facebook platform.
Keep in mind that games are very different from other products. You tend to have lots of them for a short amount of time, then they move to something else. It's not like a service like Dropbox where once acquire you have a very good retention.