Top reasons to use 301 Redirects

1. Making sure that the search engines see only one site.
   If you don’t identify to the search engines that your primary domain is
   www.yourdomain.com they will think you have two domains for the same
   one when someone enters yourdomain.com.  A simple redirect code added
   to your server makes sure that the search engines give you credit for
   just one domain instead of two being in conflict.
2. Moving your current site to a new platform.
   This is the most popular and frequently used application for the 301
   Redirect. When you move your site to a new platform the number one
   thing to consider is what happens to the pages that are currently
   indexed or bookmarked. Without telling the browsers the page has moved
   they will get a 404 or Page not Found error. Luckily, in our system the
   404 Error still displays the sitemap so the user can still navigate to
   the page they were looking for. However, using 301 redirects can help
   avoid the “page not found” errors altogether which is the best case
   scenario.
3. Renaming a page on your current site.
   Maybe you misspelled a URL and didn’t catch it for a few weeks/months
   after the site launched (it happens). Now you want to correct it, but
   you don’t want to disrupt any links that might exist to the previous,
   incorrect, version of the URL.  Make sure you use a 301 Redirect even
   if the misspelled URL was only there for a brief time. Chances are
   Google already knows about it and has it indexed.
4. Changing your online strategy.
   Many times we need to change the structure or focus of our websites in
   order to direct people down the path that will lead them to convert
   into a sale/lead. Sometimes this change means creating new pages or
   just restructuring the navigation of your website. When we restructure
   navigation, it is good to remain consistent with the menu name and page
   name. This means that your URL will more than likely change in the
   restructuring of your site.  When you change the URL you need to
   remember that the current URL is indexed and people may continue to
   visit it, so don’t forget to add a 301 Redirect just in case.
5. Traditional Advertising.
   When you run an ad in a newspaper, magazine or on the radio, you may
   want to give it a unique URL (i.e. “yourdomain.com/SaveNow”). For most
   of these ads you will probably want to create a new page, but there
   could be circumstances where you want to use an existing page. If you
   already have a page created and you don’t want to duplicate or share
   the content between the pages, then a 301 Redirect would work perfectly
   to redirect your ad traffic.