Value:
'Internal Links' indicates the number of hyperlinks to pages, files, or other objects
within your web site's domain. Links to other sub-domains or third party web sites
are not considered internal. These types of hyperlinks are known as
outbound links.
Recommendation:
There are no specific recommendations on the number of internal links to have on
a single page, other than to limit this number to 100 or less.
Exceeding this value
may indicate to Google that the page is part of a link farm.
Tip #1
Sitemaps will commonly exceed this number, so it is recommended to split them up
into multiple pages.
Tip #2
Make sure to use keywords you wish to rank for in the hyperlink text. For example,
if a page is about tennis shoes, you may want to use the keyphrase "tennis shoes"
in all links pointing to it.
Tip #3
Make sure not to use the same link text for multiple pages on your web site. This
will dilute the importance of a keyword to a specific page.