Below are 4 really common scenarios that can cause your site
to inadvertently expose multiple URLs for the same content. When this
happens external sites linking to yours will end up splitting their page links
across multiple URLs - and as a result cause you to have a lower page ranking
with search engines than you deserve.
SEO Problem #1: Default Document
IIS (and other web servers) supports the concept of a
“default document”. This allows you to avoid having to explicitly specify
the page you want to serve at either the root of the web-site/application, or
within a sub-directory. This is convenient – but means that by default this
content is available via two different publically exposed URLs (which is
bad). For example:
http://scottgu.com/
http://scottgu.com/default.aspx
SEO Problem #2: Different URL Casings
Web developers often don’t realize URLs are case sensitive
to search engines on the web. This means that search engines will treat
the following links as two completely different URLs:
http://scottgu.com/Albums.aspx
http://scottgu.com/albums.aspx
SEO Problem #3: Trailing Slashes
Consider the below two URLs – they might look the same at
first, but they are subtly different. The trailing slash creates yet another
situation that causes search engines to treat the URLs as different and so
split search rankings:
http://scottgu.com
http://scottgu.com/
SEO Problem #4: Canonical Host Names
Sometimes sites support scenarios where they support a
web-site with both a leading “www” hostname prefix as well as just the hostname
itself. This causes search engines to treat the URLs as different and
split search rankling:
http://scottgu.com/albums.aspx/
http://www.scottgu.com/albums.aspx/