At 5k users as of March 2017 they are growing 10-15% weekly. If a customer ever tried to send or receive encrypted emails of any kind, the customer probably immediately gave up email privacy - the tools available are not intellectually accessible - it takes a lot of technical knowledge to set up and use. cryptup is breaking the gap between what people want to do (protect their personal and corporate data) and what tools are available that they actually want to use.