Value:
'Outbound Links' indicates the number of links pointing to other web sites. This
also includes links to subdomains within your primary domain.
Recommendation:
Although there are no specific recommendations on the number of outbound links to
have on a single page, it is recommended to limit the number of outbound links as
much as possible. Although linking to relevant sites can sometimes be beneficial
for SEO, it can also hurt your page rank.
Tip #1:
Having too many outbound links can give search engines the impression that your
page is a "doorway page".
Tip #2:
When linking to other sites, you can use the attribute "rel='nofollow'" to notify
Google (or other search engines) that you are not trying to up the page rank of
the site your linking to. This will keep your site from being negatively affected.
Although this attribute was introduced to combat comment spam, it can also be used
to keep your page rank from being docked when linking to other domains. It is recognized
by the major search engines, although some smaller engines will simply ignore it.