I would recommend trying an upfront or recurring fee first. If that doesn't work then try advertising/referrals. It is easier to implement and will generate mor

I would recommend trying an upfront or recurring fee first. If that doesn't work then try advertising/referrals. It is easier to implement and will generate more revenue in the short term if it works. Don't worry about scaring people away at this stage. You actually want to find the people who really need this service so you can figure out what they really want and care about and build those features. If someone pays, that means they really want it.