I run Nomad List (https://nomadlist.com) which is not exactly a SaaS but it is a subscription revenue based company. It just passed $300k/y
I hear a lot of customers clamoring for the old school pay for listing, get inquiries via emails method, particuarly after the big guys in the space are stumbling: https://www.consumeraffairs.com/news/homeaway-vrbo-service-f...
It's not my main focus atm though!