Adding a level-up system can create more engagement and brand loyalty on the users profile. Members can level up their points by replying on comments, creating a post, participating in certain events or quizzes etc. And possibly redeem the points for "rewards" by prestiging etc. These rank up systems can be useful towards matchmaking as well because this can cause ranks to match up with people who are at a similar "level" as them. Things to consider about this as well will create: more competition, points farming etc. But the overall idea is to build and create a more engaging and loyal community. (Similar to how credit cards are used; receive points to redeem for a flight to go to hawaii etc.)