Getting listed in 20 directories isn't as good for conversion, in my opinion as getting a lot of traffic from a targetted forum where you might get Dugg, Facebook noted or anything else in the social networking area which will build more traffic.
Getting listed in directories gives no conversion at all... Especially when your link is buried three levels deep in zero-PR page.
I totally agree. But not only that, some directories die naturally but you won't know it. Some even requires reciprocal link and putting their widgets on your site. I wasted my time before submitting my blogs to over 100 directories. I should have spend that time in forum posting, a real win-win situation between me and fellow members.
but every little backlinks counts. I would say if you have time and already tried other methods, directories still a wise choice.