It has been a while since I last spoke with them, but don't they charge based on audience size for their messaging capabilities? Seems like they and other mark

It has been a while since I last spoke with them, but don't they charge based on audience size for their messaging capabilities? Seems like they and other marketing platforms are all trying to get customers to pay for messaging on their own properties (vs. email). I'm ok with paying for storing audience data (although portability/vendor lock-in are HUGE concerns), but paying for reaching my own visitors outside of email seems a bit much.