I must say that Zortrax Marketing machine is working very well....Sometimes to good ;)
Why don't you make a popup window in Z-suite with tips of the day...And when you have a big announcement like an update,new material,etc... you inform all zortrax users about goodies :).
Just let it popup and the user will know what's going on. Or make a dashboard thing (also) like many other software companies have. Integrate this forum in it just like you did with the library tab in zsuite and make a file browser window with stl previewer so that users do not have to open every damn file.
And you can stop sending emails to buyers who don't know a thing about Zortrax and his products and you will inform the end users who are actually using your products and also ordering your products. And don't worry I do get enough emails every day.
Oh and before I go make a plugin available for all major CAD resellers like Solid Edge, Solidworks, Inventor....
I work with solid Edge and many users are asking questions about integration of 3d printing software in to CAD software