Look at it this way...blog directories usually work similar to top lists. The more You send to them, higher You go up and more You'll get from them.
LL's on the other hand list blogs like free sites meaning it doesn't matter how much You send for as long as You keep their link.
To explain a bit further I'll have to use an example ... mine of course
You're blog will appear on several pages like this:
Main page - page is changed daily with new submissions.
Cat index page - page change depends on submits to the category. At all times latest 5 blogs are displayed so here blogs are listed by date.
Main blog directory page - page changes with submissions and blogs are listed by date.
Category blogs page - list sites alphabetically and change starting letter every day in order to give each and every place same exposure (if possible).
Now, this is just one example of how it’s. Others do it in a similar fashion but the key issue here is that none is counting clicks .