It's very easy to use for our website when we want to cache some part of it, so that people can get faster load speed in their devices! We have several websites cached by this program with great performance improvement compared against other caching tools which was not as good at all or even worse than us using them directly from AWS EC2 instances if possible (which is expensive). I don't know how much money they make but my guess would be more like $100 per month just because you need one instance running 24/7 only serving your clients while others are idle most time without costing anything extra except having an internet access where needed.