It's even worse if you arrive at the landing page with an old browser: Then the most important thing the team wants to tell you with their single shot at your eyeballs is that they are uber-geeks who love web sockets. Like I, as a potential customer, should care about that.

I'm guessing here, but they should be able to build a landing page that tells me what their product does without needing web sockets to build it. Without it I'm not even going to make the effort to come back later on a browser that they might support just to find out what on earth their offering is.