Originally Posted by Bossman

Its much more easy to brand a good domain - especially if you wish to go beyond affiliate marketing (even with only affiliate marketing you will get more potent traffic with a good domain). Once things go viral, then a good domain will pay itself many times over (easier to remember, tell others about etc.), and its much more likely to become part of the everyday slang/language itself, which will drive even more traffic.

A good domain with a good product + marketing plan will beat an average domain with good product + marketing plan. Now the question is just, if you can afford the good domain to get a head start for your good product and marketing plan.