Suppose you run a professional services business where you have appointments. If people don't come to an appointment, you don't get money. You might pay an office manager to call people the morning of their appointment to remind them, so that they come into their appointment, so you get paid, right? Appointment Reminder is like an office manager who costs $200 a month, not $4,000 a month, is vastly more likely to successfully reach a customer, (virtually) never forgets to call, and does not consider boring, repetitive work to be an insult to her intelligence. For many of my customers, $200 is substantially less than they earn for a single appointment. (Think less "hair salon" and more "HVAC repair firm.")
I didn't mean appointment reminding in general - which is a good thing obviously. But I thought it was a long time solved problem by other means (and not necessary by office manager), be it some "enterprise" calendar or todo software which are integrated in most of the "enterprise"/business software products, etc...
Substantially all problems were solved by someone else first. That doesn't meaningfully inhibit you from solving them, too. Reasons why this could redound to your advantage include superior marketing, positioning, ability to attack different niches, lower cost structure, or the ability to survive off the crumbs the big guys don't care about.
It's totally worth it for me to have the CEO and head of product development talk to your office manager for 30 minutes then custom code an import script, to get you onboarded at $200 to $500 a month. The 800 LB Gorilla basically doesn't care about you below $1k a month.
The crucial detail is that some small HVAC company may not even be using an "enterprise/business software product"... In fact they're probably still keeping appointments on a sheet of paper.
I'm used to my dentist's office manager calling me every six months to remind me about my cleaning appointment. This last time, the call was automated and I instantly thought "hey, Appointment Reminder."
No, it turns out it was SmileReminder that the dentist uses. When I went in for the appointment I spoke to the office manager and the light in her eyes was obvious: "Now I don't have to spend hours calling everyone to remind them. I love it" No idea how much they pay for the service, but it's obviously worth it to them.
The medical field is one of the few where you feasibly can charge somebody who doesn't show up. Joanne the hairdresser down the street can't do that because she doesn't have all of your info down to your SSN and in fact she doesn't even have a collections department. Joanne's only recourse is to sit there twiddling her thumbs.
(And, BTW, I know several hairdressers who can go well over $200 for a single appointment.)