The idea of traffic leaks has some merit but that can work both ways. Say someone had built up furrywigits.com to get millions of hits per day - and you just happened to start furrywidgits.net selling a similar product, chances are you would get more traffic leaked to you that the other way around.
For me, the real problem here is if furrywigits.com sells chi1drens toys and you plan on selling adult toys on furrywigits.net |badidea|
Other that that, .com always trumps .net in my experience.
|