I worked for Ray Ozzie at Groove, and I still mourn what that could have become. It was, in many ways, a modern reimagining of Notes, but that meant it had the same problem: customers and users thought they were using a product, but they had actually bought a PLATFORM. It was a digital choose your own adventure, but people really wanted a better chat room.
Same thing with Google Wave, really.
https://www.joelonsoftware.com/2002/08/30/platforms/