MongoDB is valued around 15 billion dollars right now. You can argue that they are not really open source, due to their new license that is not OSI-approved. But it’s pretty close, and it’s something that aspiring open source businesses should consider. It’s basically “almost entirely open source except AWS can’t offer your product as a service.” To many people, that is just as good as open source, and if it makes the business model that much better, maybe it’s a good trade off.