I am currently in the process of building a community around projects at my University. So far, I haven't been able to grow real traction or provide great value. But I believe the idea is solid and has the potential to help a lot of students and teachers.
I've been talking to people about the idea and my approach so far. What I learnt is that you can't expect to create a platform and hope that people would use it. You need to go out and find people that are like-minded and invite them to join the journey. You need to be persistent and pull a lot of effort. Nothing comes easy.