My Use case:
- like many online stores & offers, losing track of customers after they have bought is easy, - unfortunately as, "once a person have bought from you (and are happy ;-) ) it is much easier/ cost less - to sell to that person again, than finding and selling to someone who's new and still a stranger..

But most CRM solutions often are complex and and time costly to set up, and often you have to created (resource consuming) content to keep somekind of connection. You never or very late come around to get such set up.

When what you want the most - is to know, what buyers think of the product (so you can improve, know if & what further to sell to them etc.) or if very satisfied, you can communicate this as a testimonial in your efforts to attract new customers & create trust in the sales process etc.

In this manner Saastic, helps a lot, as its much easier to set up than a complex crm.

Last,
- I had a couple of Q's and got the fastest & valuable answers from Scott Vayner at Saastic.

So both top app & top creators!