Good article from Eric Ward of the Search Engine Guide about the value of links from niche directories and how its not about the number of overall links but the quality of the links.
Some comments from the article:
Most people will tell you that links from Yahoo and DMOZ to your site are vital, and to a certain extent I agree. Who wouldn’t want to be listed with two of the most widely used directories in the world? It’s what marketers do after they get the Yahoo and DMOZ links that can make or break them.
Niche and topical search engines and directories can bring your site highly targeted traffic. Maybe not a stampede of it, but a steady trickle of perfectly qualified users. And while some marketers are quick to claim nobody uses niche search engines because they’ve never heard of them, I can tell you from ten years of experience they’re wrong.
I would agree here and its very key for legal web sites to get links from other legal related sites and especially ones that would related to the practice areas of the firm. For example, a Chicago Construction law firm would benefit from getting a link from a construction law category at a legal directory. This would not only drive focused traffic to your site, but would be a more valuable link then many links from non legal sites.
Its key to get links to your site and the more you have, usually the better BUT I can show you many sites that are very well ranked at Google and don’t have more then 25 links but they do have good links from Yahoo, the Open Directory and other key legal sites.