Some day you will probably figure out that some SEO relevant parts are for some reason not optimal on your website. Maybe it has not really been considered how SEO can affect the product planning right from the start or there are happening some bugs with nasty SEO side-effects. The problem is that some SEO changes need to be done very carefully to avoid unnecessary problems.
Fundamental URL changes
If you are thinking about major technical feature changes for your website it might become necessary to change the URL structure of your website. In any case, this kind of SEO changes need to be very well-planned, especially if the website is big and complex. 301 redirects for any type of old URLs you already have in the Google index to the corresponding new ones are a must to avoid loosing link-juice and 404 errors.
Moving to a new domain name
If you really think you have to move your website to a new domain name, please make sure that you announce this to Google via Google Webmaster Tools to Google to avoid problems. You can find the form for domain changes in the “website configuration” folder of Google Webmaster Tools.
Changing features without thinking about duplicate content issues
It is actually easier to produce duplicate content as it seems, especially if the updated features are dynamically generated. Well, a smaller % of duplicated content is not too bad, but if major parts of your website are basically duplicated you can get into trouble.
No proper testing after change
So… finally, your super-important SEO fix is live and you are already dreaming of the results it will (hopefully) bring… So far so good, but don´t forget to test it! SEO-testing your website deeply after deploying an update is very important! Did you test for broken links? URL-structure is still ok? Website speed? etc. Well, maybe Testing is not the most exiting part of the job, but there lots of cool tools that you can use for more effective testing, like automatic link checkers, Selenium tests etc…
Introducing new product features without thinking about SEO
Whenever there gets a new feature introduced it should get reviewed by SEO, especially if it adds or changes the internal link-structure. Don´t get me wrong: not every feature needs to add SEO-value to your site, but you should avoid that it harms your SEO.
Thinking Google Webmaster Tools shows all SEO Problems
GWT is a great help for webmasters and SEOs to check their site and reports all unwanted issues like for example error 500 or unreachable errors etc. But no errors reported in GWT does not necessarily mean that everything is fine. One example: You can´t tell if all 301 redirects work correctly. If a redirect goes to a wrong page it won´t get reported by GWT. Only if the incorrect redirect goes to an error page, then it will appear.
I hope this list was helpful for you! Feel free to add a comment and tell your experiences about SEO side effects.
A big thank you to Thomas Fuchs-Martin of Web Product Blog for this guest post!