I have a question: at a previous startup we emailed and called small and micro businesses in NY-SF-LA to sell an SMS marketing service. Kinda like messagebird b

I have a question: at a previous startup we emailed and called small and micro businesses in NY-SF-LA to sell an SMS marketing service. Kinda like messagebird but not for developers. Basically a web app to be able to send a list of numbers an sms with one tap, in an automated fashion. Out of 4000emails/calls, which were not pushy at all and focused on understanding their needs, no one ended up paying ($3.6k/y). What do you do differently?