you will find that only a small amount of people will link back as no one will out there as there lazy, the thing is with dirs people like the dir to have high PR these days, I my self dont as long as its got really good traffic.
Remember people are out for them selfs, well most of them so this is why link backs to you will not happen alot
as for :
"Comppared to backlinks, how effective are outbound links to the site that hosts them?"
sorry I didnt understand this
