Thursday, March 4, 2010

Lessons from the field – The impact of changing your website structure on search engine rankings.

Your website was working well, you agreed to changing a few things to improve the site and in just a short time your website’s PageRank dropped from 5 to just 1 and you lost 40% of your hard earned traffic overnight.

It is the stuff of nightmares but this actually happened to one of our customers and yes, it can happen to you.

There were several factors involved. These included:

  • Restructuring the website to optimise the URLs for search engines.
  • Adding geographic redirection based on the country where the visitor is located.
  • Changes in the technology used to deliver the site.

The critical mistake made was that the changes to the URLs resulted in lots of broken links. Some URLs redirected to their new location using 301 server side redirects, however the number of redirects required was vastly underestimated and this led Google to drop the website’s PageRank dramatically. Google also dropped a large number of pages from its index.

Our customer tried to fix this by adding XML files to the site and submitted these to Google via its Webmaster Tools. This was partially effective but didn’t fix their rankings.

The actual fix was to thoroughly audit the website and changes and then implement a rescue plan, the first step of which was to correct all broken links on the site. As the site had good quality inbound links getting the errors fixed resulted in the rapid inclusion of the new pages into Google’s index.

Following the implementation of our advice, the site has since returned to a PageRank of 4 and traffic from Google has slowly recovered over the past two months.

So what could they have done better?

Firstly they should have carefully planned and more importantly tested the redirections from the old URLs. Had the client run a simple link crawler over the URLs from the old site structure they would have easily identified the problem before it happened.

Secondly in the panic to fix everything they made so many changes so rapidly it was difficult to identify what happened and to unwind the negative changes.

Thirdly they also changed the structure of their pages including the keywords used in page titles, headings, links etc.

To prevent this from happening to you:

  • Treat any proposed changes to your URLs as a significant threat to your search engine rankings and put in place a strategy to manage this. (Changing to or from a content management system is a key risk factor)
  • If you do need to restructure the site, then start by building a comprehensive inventory of URLs. This can be done using your web analytics tool or from the web server log files.
  • Identify the top keywords used by visitors to locate the site and the pages that rank for these keywords in Google and other search engines.
  • Ensure that as much as possible that the page structure and links used to point to these pages remain as close as possible to the earlier site.
  • Redirect all new URLs to the exact alternative URL using a 301 server side redirection only. Nothing other than a 301 redirection will work correctly.
  • Any page that can’t be redirected to a new location should use a custom error page. This custom error page should return a 200 status code if the page is to be retained in the index.
  • Test all redirections using a site crawler to ensure that there are no errors.
  • Monitor your site carefully using a quality web analytics tool such as Google Analytics, Omniture, WebTrends or similar. You should be the first to know about any changes to your search rankings from a rise or drop in the number of visitors from your previous keywords.

If you would like professional assistance to manage any change in your website and its impact on your marketing and search engine rankings please contact Panalysis to discuss your requirements.