LinkedIn isn't typically associated with gaming in the classic sense, but there are a lot of fun ways people use it for career development and networking that can feel game-like. Here are a few ideas:

At LinkedIn, our goal is to continue providing a safe and trusted platform for professionals to stay informed and connected...We are looking to provide a quick bite size pause for people to exercise their brains but also, we want the games and questions to be starters for good conversation. We wish these games become an instrument of banter, conversation, or a bit of competition between the professionals across globe.

Networking Challenges - Launch a challenge to ping so many professionals within a week/month etc.