"Links" are the means by which one who navigates a web
site is able to 'jump' from one area of a page within
that particular site to another area on the same or a
different page, even to a completely different address.
Frequently checking the links of a web address is an
inexpensive means to verify that your site visitors
are accessing a well maintained, properly connected
environment. Dead links which result in the dreaded
message "404 error - Page not found" reflect poorly
on inattentive site owners. Surely, once a customer
has arrived, is it not rather poor form to point to
Webmasters and a goodly number of developers are also
sticklers to assure proper connections during stages
of refinement and after uploading. Continuing to test
afterwards is a sound practice, as it recognizes that
Murphy's Law does not catch one on guard by surprise.
Finding the hole(s) early can save lots of heartache
(as when a critical link is recently out of service,
on the blink, inaccessible, been renamed or dropped).
Unfortunately, only when you are aware of a problem,
can it be addressed.