Do you mean when they open a channel for you?, there's a fixed 3k sats fee for that, so it would make sense that they make some money from that. It's not only when you start using it, it's every time you receive more sats than what you currently can receive.

Phoenix is also their own LSP. I'm curious how their numbers look with respect to routing fees and if they make an amount close to what it costs to run their infrastructure. I think Mutiny's forward looking approaches regarding coinjoin / DLC services could be lucrative