Duplicate content issue always stays hot in almost all webmaster forums. There will be someone keep asking about duplicate content issue in SEO forums. I have answered some of them but these seem to be a continuance similar question posted by new webmasters who explores search engine optimization. Most webmasters prefer to use several tags for each article posted on their blog or website to increase search engine traffic for any particular keywords. Tags do help to get more targeted traffic to our site if we can manage to rank well in search engine.
If the same article using 5 to 6 different tags under one category, then the same content will be shown on 7-8 different pages. This will implicate duplicate content issue with most search engines like Google and the result could be damaging. Most probably, the first indexed and cached page will be shown to the users and the rest of the pages will go into secondary results or sandboxed. You are lucky if the first page indexed is the exact URL permalink or any of your preferred type of URL (category or tags links). We can control this issue with some simple step.
There are not many wordpress blogs install SEO plugins. They should install at least one SEO plugin for their blog to enable canonical tags. This will greatly help your site in search engine optimization where the main site will get the credit from all tags and category or any other duplicate content page links. Of course, it may not give much credit in SEO rankings but it will certainly help your site to get more indexed pages. This will also help your pages to stay away from sandboxed. Usually, search engines will not index all our pages.
You can also edit robots.txt file to stop search engine from crawling duplicate contents. Search engine optimization scripts are available for almost all type of open source platforms. Let it be wordpress, drupal, zencart, etc; there are SEO modules available for free of use to improve your search engine placement and rankings. However, you can also manually add canonical tags on duplicate pages but I don’t suggest this method. Using a well known platform is a safe way to run your business or blogs. With constant updates, you will enjoy secured environment that will keep the hackers out.
Personally, I use All In One SEO Pack plugin for all my wordpress blogs. You need to donate some money before using it. However, they don’t really check or making it a compulsory to donate. You can always tick “I have donated” and start using the plugin. Once you have some money earned, then you can consider donating some for their excellent work. I couldn’t imagine of doing all the onsite SEO for my growing wordpress blog with almost daily updates manually.
Spam filter plugin, Akismet comes in default wordpress now. There should be Google XML Sitemap and All In One SEO Pack plugins comes in default too. The importance of these two plugins in wordpress SEO is extremely high. It gives an upper hand for all wordpress blogs to get higher ranking of search engines much quicker compared to any other platform.