While I've been playing with Postach.io I've discovered Intercom, the product that drives their support approach. Within the Posatch.io web app you can click on a "question mark" icon down at the bottom right to ask questions, get answers and have a dialogue with the developers/support team. It looks deceptively simple and straightforward, but the underlying platform seems to have lots of clever stuff. Intercom describe their product as a "next-generation CRM and messaging product". They say it helps web businesses build relationships with their users and turn them into loyal customers. The pricing looks good - a free version and then $49 a month. I've been looking at online support options - this approach definitely looks worth checking out.