Free plans sometimes work and sometimes don't. A good example of where they (at least seem) to work well is Calendly. Every time you use the service you adverti

Free plans sometimes work and sometimes don't. A good example of where they (at least seem) to work well is Calendly. Every time you use the service you advertise it (even when on the free plan), and if I had to guess, a good amount of people eventually become paying.