If users are not doing what the designer intended (when users are investing time, effort, etc in your product), the designer may be asking them to do too much.

User habits are a competitive advantage. Products that change customer routines are less susceptible to attacks from other companies.

Companies leverage two basic pulleys of human behavior to increase the likelihood of an action occuring: the ease of performing an action and the psychological motivation to do it.

Brainstorm new interfaces that could introduce opportunities or threats to your business.

Like flossing, frequent engagement with a product, especially over a short period of time, increases the likelihood of forming new routines.

When designers intentionally trick users into inviting friends or blasting a message to their social networks, they may see some initial growth, but it comes at the expense of users' goodwill and trust. When people discover they've been duped, they vent their frustration and stop using the product.

Reducing the thinking required to take the next action increases the likelihood of the desired behavior occurring unconsciously.