I use a really ancient version of
wsnlinks for my
property investment directory and if they've continued with the same quality it should be worth the $$$
I've recently started a
New Zealand Directory, half heartedly and only to expose the clients of a
pro forma scammer and it uses
link manager assistant - a free script but it has 4 links at the bottom you can't control. I'm not convinced I'll continue with this system but it's interesting. My concerns relate to managing large directories with lots of items.
Rule: Run the links on your own site, don't use a third party company
Sarah