The ultimate goal of a habit-forming product is to solve the user's pain by creating an association so that the user identifies the company's product or service as the source of relief.

For an infrequent action to become a habit, the user must perceive a high degree of utility, either from gaining pleasure or avoiding pain.

Habit-forming products often start as nice-to-haves, but once the habit is formed, they become must-haves.

Users who continually find value in a product are more likely to tell their friends about it.

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.

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

You'll often find that people's declared preferences - what they say they want - are far different from their revealed preferences - what they actually do.