Add elements of unpredictability and curiosity.
This is one of the most important psychological mechanisms in almost every application that we use on daily basis. We open our mailboxes, Facebook, and Instagram because we are curious to see what’s there. It’s unpredictable. This is why Groupon got so successful as well.
If your product does not offer a strong utility that a user will have reason to use on a daily basis, it better have something unpredictable.