About your question on whitelabeling: I wouldn't be too dogmatic about this either way. It's easy to make it a question about your company's mission, but it's more of an ROI decision. If you're seeing strong demand from companies who will pay you well for a white-label version, and your software is written in a way that makes it easy to build one, you should do that. Otherwise, it may just be a distraction.
The other thing that jumps out to me about your business is that the economics don't seem to match with the usage. You're serving a lot of traffic but not making as much revenue as I would expect, especially considering that you have "die-hard users" that love the service. Perhaps you can find a way to get them to pay more money, or find other customers that can afford to pay more?