Link Popularity. What you want here is a lot of links from a lot of unique domains. You do not want 10,000 links from one domain/website. You want 10,000 links from 10,000 unique domains. A general rule of thumb is the more links you have, the easier it is to achieve top rankings on search engines such as Google.
Further reading on this topic here.
Directory @ V7N
This directory lists only quality websites, and it sends some impressive traffic due to the placement of the V7N Directory search box on many, many high traffic sites.
A professionally edited web directory, currently operated by the V7 Network. Submission is highly recommended.
Editors seems to suffer from paranoia in that if you own – or are affiliated with – more than one site, they might accuse you of spamming if you submit more than one site for review. Submit, but don’t get your hopes up.
WOW is now an established web directory. Professionally edited. Submission is highly recommended.
AbiLogic is one of the better submission rates today. Submission is highly recommended.
Professionally edited web directory operated by Peter Da Vanzo. Highly recommended.
A volunteer edited web directory. Submission is recommended.
Another very active, volunteer edited web directory. Submission is highly recommended.
A pay directory. Affordable and recommended.
Umdum is owned by Loren Baker, and he’s done an awesome job of promoting this directory.
Yahoo! Web Directory
Most categories will cost $299 per year. It may or may not be worth the cost, depending on the category.
A volunteer edited web directory. Become a volunteer to add your site.
A great place to advertise.