The points and achievements earned for using a website is an example of gamification.
gamification - Computer Definition
Applying gaming principles to non-gaming websites in order to engage more with the public and increase traffic. Gamification is reward based either with points, titles or freebies. For example, if people recommend an offer on a website to enough takers, they get a free item. Gamification is expected to be a major trend with social networking sites, as well as ordinary websites and applications. By adding game-like experiences, users are encouraged to return more frequently to try their luck, hone their skills and reap more rewards, which may be nothing more than the satisfaction of accomplishment.