Why do Educational and Government links matter?

and do all links sitewide weigh the same

[DXL]

I've seen a lot of talk over the years about the benefit of getting a link from an .edu or .gov site, but not much in the way of explaining what their inherent value is (maybe because of the PR value, the number of inbound links they share, content, lack of links to bad neighborhoods).

Can someone explain exactly why a link from an educational site is considered so valuable? And if link value differs between placement on a main .edu page (mycollege.edu/campus.html), a department page (mycollege.edu/chemistry/main.html) and a subdomain such as a student's personal site (students.mycollege.edu/martinibuster/springbreak.html)

[digitalghost]

The reasoning follows along these lines:

.edu and .gov domains are considered to be authoritative. In addition, it's likely that those domains have been in existence for quite some time, (domain age). until a few years ago, it ws doubtful that you would find a link to say, a casino aff site from an .edu domain. Linkflation has changed that to some degree but you're still more likely to find the qualities of a good link from an .edu or .gov site than you are from some MFA site.

Apart from those two factors, look for the same qualities in those links as you would any other, number of outbound links on the page, link placement, relevance, value to the end user, etc.

>>and do all links sitewide weigh the same

No, and they never have. Think 'per page' and then think 'per link'.