You do not want to have each client poke your server every 1 second. Just make the math: 1000 requests every second. As soon as one of the request starts taking more than 1 second, you will slowly start to launch a Denial of Service on your own server.
I don't know if you are in the ASP.NET environment for the server, but if you are, I suggest that you take a look at the SignalR library.
A typical demo app for SignalR is a chat program. See ChatJS or Jabbr.
You can follow this tutorial to learn more about SignalR.