“Cost” may be monetary or an investment of time. Is your service priced accordingly? What items can you withhold until they are earned—perhaps a new feature or privileges? On pricing pages, offer a range of packages and highlight—or at least offer—a more expensive one than you think most customers would choose.

Attractive things work better—or at least we perceive them as being easier to use. Have you evaluated how attractive your application (or site) is to your users? We are more forgiving of attractive designs and assume they are (or should be) easier to use. The curious part? A well-designed site is often a more usable site.

While commonly used to promote purchasing behaviors, limited durations can also be used to shape day-to-day behaviors. Set limited times when certain actions can be taken. Make rewards available at specific times or have options that disappear if no action is taken within a specific period of time.

Are actions tied back to a profile or an identifying piece of information? In online social contexts, sharing actions (or a subset of actions) with others helps encourage good conduct. People build reputation through things like sharing information, connecting people, and keeping a record of their personal activities. While identity is often site-specific, consider ways to use the external identities people have built.

Are there any small surprises in the experience you’ve designed? “Surprise” could be a new addition or a variation on something routine, such as stating a confirmation message differently or changing an image on a familiar page. Also consider how you can get people’s attention by deviating from expected patterns set by other sites or experiences external to your site.

What are the peaks and endings in the customer experience you’ve designed? Peaks may be the core value you provide or a small surprise thrown into the user journey. Endpoints can be obvious (order fulfillment from an e-commerce site) or more subtle (such as a friendly or funny registration confirmation page). Identify and improve these.