...And this is why every startup should use intercom [1]
intercom will let you do exactly what the OP suggests: segment and message your users based on how they use (or don't use!) your product, as well as who they are and how important they are to your business!
disclosure: I am an early investor. but don't worry, intercom will be around for a while: they just raised $23M from Bessemer [2].
[2]: http://insideintercom.io/silicon-valley-outsider-raised-30m-...