Benefits of toplists?

[Tart]

I've always wondered, and well darn it, I finally decided to ask.
I've always avoided toplists after being a newbie surfer and getting trapped on a few clipart ones (I know you all have been there hehe) Once I started building sites, and saw that I had to send hits to be listed, I also avoided them as it didn't seem to be as good an investment as giving that link out to a regular linklist.

Toplists still do seem to be going strong and I'm curious as to the benefits they provide to both the webmaster running them and the webmasters submitting to them. What are the pros and cons?

Thanks for any insights!