1. Serve your users’ narcissism. Daniel Carnegie has already said that the sweetest word in all languages is your name. It is one of incentives exploited by Twitter. Anytime someone uses your @name in a Tweet you see it.

2. Measure behavior and report it. Foursquare gives points every time the person checks in. You are also shown when someone of your friends or people from your area check in. Foursquare reports how big a loser you are because there are 34 people from your area who’ve checked in more than you this week.

3. Add status for behaviors. Show how many times the person has checked in, what his achievements at this app are, etc.

4. Make multiple status reports. Foursquare reports how much status each person earned, but it also tells who is the mayor in some area. That is two ways you can see status, and get addicted.

5. Make undesired behavior seem lame. “Why is everyone finally putting their photos into Twitter? Because if you don’t have your photo in Twitter the icon it puts there looks, well, lame. So, Twitter is putting a subtle enticement to all of its users to upload a photo”.

6. Make it easy to share success with others. Information about your mayorship or changes in your status can be shared also per mail, per tweets, they are shown on your wall and on the main page on Facebook

7. Make an API for studying behavior. Developers love to build apps to study data and report that.

8. Make it easy to join in other users. Facebook makes it very easy to tag your friends in a photo. If your friends aren’t in the system it makes it easy to invite them.

9. Give people more “hooks” to addict their friends.”Facebook, for instance, asks you what your relationship status is, and what your political persuasion is. Why does it ask you those? So you’ll force your friends to join!!!”