That's strange for hn because it's known that in a vast and rich sea such as the IT world, stability leads to a slow/fast failure or disappearing. They'll have to innovate, for their business and for the users.
And yet the reverse is true too. Over-innovating which I see as almost universally putting form ahead of function kills web enterprises dead too.
I think craigslist is a great example of success going with the most minimal "innovation" - in the last ten years I can think of two changes there, and one wasn't even voluntary. First, the map-view for housing listings and second the giving up of sex services to other sites like backpage under threat from a bunch of point-scoring district attorneys.
