1. Keywords in anchor text (individually)
2. Keywords in anchor text (exact phrase match)
3. Keywords anchor in text (order of keywords if not exact match)
4. Length of anchor text (in words, not characters)
5. Placement on page
6. Proximity of non-link text
7. Proximity of link text
8. Density of surrounding non-link text
9. Density of surrounding link text
10. Relevancy of anchor text (to the page it's on)
11. Relevancy of anchor text (to the landing page)
12. Relevancy of anchor text (to the rest of the site)
13. Number of links on page using same anchor text (exact match)
14. Number of links on page using similar anchor text
15. Repeat 13 and 14 for entire site
16. PageRank of page link is on
17. Depth of page (subdirectory-wise) that the link points to (in relation to the page it is on)

Hello
Determine the Page Strength

And I’m not just talking about Google PageRank. It’s been known for awhile that the simplified PageRank (which is most commonly seen in the Google Toolbar) is not actually your real PageRank; that is a much more complex number kept by Google. Although don’t delete your toolbar just yet, PageRank can be a good first impression. If a directory, especially a paid one, has a PR below 2, chances are it’s not worth the link.

Another common form of page ranking is the Alexa Ranking System. Like Google PageRank, it’s more of a safety net than a valuable resource, but generally directories which fall below the 100,000 mark on the Alexa scale are going to be worthy of a link.

I prefer to use the LinkScape tool over at seomoz to determine Page Strength. It provides more detailed data than both Google PageRank and the Alexa Ranking. They offer a number of free tools, but if you’re serious about pursuing SEO, you should definitely sign up for a PRO account.

Here are some things to keep in mind when evaluating Page Strength:

Don’t Just Check the Page Strength of the Home Page
Is your link going to be placed on the homepage of the directory? Chances are no.

Check the Page Strength to the Page Your Linking To
Before submitting a link, find the page on the directory where your link will appear. Look to see how the links are organized (a lot of them do it by PR, some sort on a first-come-first-serve basis; others have a bidding system, etc.). If you’re link is going to end up on a low ranking page of a directory, you probably shouldn’t submit. It’s true the overall strength of the domain will help build your link strength, but the page your link appears on is more important than anything else.