Why pay $8/month, right?
Groupsville is not the only open source social networking software out there. There are many great efforts visioning the same, replacing Facebook with something more privacy-concerned. Buddypress, Mastodon are just a couple of some of your options.
What sets us apart is our 10+ years in experience in building online communities, some with more than millions of members. Our social software is created in a unique scale-out architecture which ensures your network will perform seamlessly once it reaches huge amounts of traffic, following and popularity. Plus, it will cost much less than others to operate.
How do we do that? Groupsville is written in a unique way with an in-memory graph datastore. This is *NOT* like anything you've seen before. Thus, the difference between Groupsville and other open source stacks is similar to the difference between hosting files on a regular disk vs OpenStack, or MySQL vs MongoDB. Also, we look cooler - we think :)
For more information, check out https://github.com/phonetworks/pho-microkernel and https://github.com/phonetworks/benchmarks for benchmarks.