FWIW, I was a paying customer. I know others who were as well. Most everyone I know, including myself as of two weeks ago, has stopped paying for the service. It had gone downhill to the point of being unusable.
There is a demand for this type of service. Real-time chat is in extremely high demand still. Chat was the number one requested feature a "build-you-own" social network startup I worked at a handful of years ago even before Facebook added their chat.
We started using grove on a large client back in February / March and as of this month we are still paying clients. We started trying out flowdoc recently but we are trying out a few options between now and October. Outages aside, our clients liked the product.
Moving our team off of Grove was a bigger pain then dealing with the sporadic mini-outages so we put up with it longer then smaller teams or most companies. We really liked the feature set but just needed the product to be more stable. The writing has been on the wall for a few months as doing a twitter search will show the lack of a response for a few months now.
If they're shutting it down because it isn't sustainable, that's fine, I don't expect them to run the service as a charity (we have freenode for that!) - but that doesn't seem to be the case.
Better put: are you a paying customer? If not, then most likely other potential customers are unaware.