Many successful sites without chat. Bitzino, coinroyale, coinroll and satoshibet to name a few. Chat is nice but don't make it seen like a deal breaker.
Now that you say that I'm starting to think that having a chat might be a bit of a two-sided sword. If you have a lot of traffic it's of course great because people can see that you have a lot of traffic. If you don't, then it's not that great, bc, well, people see that you don't.
Obviously FastSlots does not have the traffic that the big bitcoin casinos like luckyb.it or primedice have. These casinos spend lots of money on advertising each month whereas I'm a bit proud that we have a decent amount of traffic now despite the fact that we spent zero dollars on advertising so far.
I'm hoping that users will not be put off by the fact that the chat will not as active as the one on those big casinos. On the other hand, I've been quite transparent in the past (eg displaying every deposit on the homepage without faking it) and I hope our players will not mind to get a realistic view as to were we are at. We will see...