As a product manager in a social gaming company, I definitely kept an eye on those metrics. However, I'd like to caution that these metrics are relevant in all

As a product manager in a social gaming company, I definitely kept an eye on those metrics. However, I'd like to caution that these metrics are relevant in all phases of the product lifecycle, but the focus on feature development follows the order you mentioned. For example, keeping an eye on Rev/DAU and conversion rates at the beginning of the product tells you about user engagement, while paying attention to reach metrics (virality and new customer acquisition) in the mid to end will give you an idea of longevity or potency of your user base. Specifically, pay attention to social/user metrics as they will tell you how active a user is in interacting socially as well as inviting new users to use your product/game.