Duplicate content can damage your website’s ability to rank in the SERP (search engine results page). Why? Imagine trying to find an answer to a question and the same answer is in four different books in your library, but you’re unsure which book explained the answer the best. In addition, you could only pick one book. You ultimately would guess and the odds would prove you wouldn’t pick the book that would give you the optimal result.
The search engines essentially do the same thing, but can you blame them? Google has ~50 billion indexed pages. Much like the example, there is simply no time to “diddle daddle.” The following graph is based on a client’s website, during which time Launch worked with the website provider to identify and correct the duplicate content. The results speak for themselves on how duplicate content can affect a website.
There hasn’t been a website that I have run across that doesn’t have some form of duplicate content. The most common are as follows:
1) No redirects or canonicals set up between www, non-www or index.php (asp, etc.)
2) Archived pages– such as author archives, category, date-based or tagged archives. Most commonly found in CMS’s (WordPress, Joomla, etc.)
3) URL Parameter issues– much like page-id having the same content as a clean URL
Now there is another one. Oh yes, and guess what…you did it to yourself. With the Google +1 button, you are essentially communicating to the search engines that you have a page that is important. So, if your duplicate content page is blocked by the robots.txt file it WILL be brought back to life by the button that you put on the website. What the h-e-double hockey sticks am I talking about? (click here to read what the robots.txt file does). If you are with me so far, then check out out the snippet below, which was posted by a Google employee in response to a question regarding this same topic:
So, what do you do about duplicate content and how do you identify it in the first place? That’s really another post. In the meantime, don’t universally add the Google +1 button on every-page if your site is built on a CMS. Use it but don’t abuse it.