Believe.
“People don’t buy what you do; they buy why you do it. The goal is not to do business with anybody who needs what you have. The goal is to do business with people who believe what you believe.” – Simon Sinek via Bobulate
This is so true. I think it’s especially true for someone who really loves your app, and doesn’t know how they ever did without it. For example, lovers of Jumpchart have to appreciate simplicity, and organization. Lovers of Staction have to understand the importance of communication with a minimal amount of clicks, and want the ability to do things quickly. We create apps as extensions of ourselves, knowing (hoping?) that others like us will get a kick out of them, and find them really useful.