I think it would be a straight numbers decision as you guess. A lot of companies would worry about how this would impact those high value and long term customer

I think it would be a straight numbers decision as you guess. A lot of companies would worry about how this would impact those high value and long term customers and how it could effect retention in other games and future projects. I think Zynga is passed that point now though (if that ever was a concern for them, they have never really been a games company a rational person would have a strong connection to). Pretty much all the big name MMOs released in the past 10 years have gracefully downsized and maintained maintenance for the player base.