How to avoid duplicate content in your WordPress blog

Most of us simply know wordpress is a tool for developing blogs/websites(news based, tutorials based), they want to earn from their wordpress blog/website, they want it to rank high in google whenever user type any search query relevant to their website but when they purchase domain, install wordpress, deploy their website then never ever they compete against any search query in google, never get traffic and remain live in darkness and then they blame that it is happening due to use of wordpress, and they think lets develop website by using plain html with server side technology like php or for their dynamic purposes :)
People develop sites in wordpress and some of them earn significant revenue but most of them are even unable to come in google against any search query, any keyword. Why? This is happen because they have blacklisted in google due to duplicate content and they don’t know about it that they have been blacklisted. Another question that I think coming in your mind is that how can we get plenty of duplicate content if we write post ourselves but I want to clear your concepts that doesn’t matter you write any post yourself by unique content, still very soon you will be blacklisted due to duplicate content. 

Now let me proof how you can be blacklisted due to duplicate content and from where that duplicate content is coming in your website. 

All of you knows that wordpress blog contains Archive, Tags and Categories Sections. Now lets suppose I have written any post for instance in the month of march 2013, you can access that post by clicking on post title in the main page of your blog or can go to that post through Recent Posts section in your blog but my dear fellows that post is too accessible from Archive, Tags and Categories section in your blog. 

Now question is how google mark it as a duplicate content? Answer is very simple, due to url. Google understand every url as a separate page, and if page is separate then content must be separate and unique. When you will click on March 2013 then the url will be, same issue you will find with Categories and Tags section. 

Now how to avoid duplicate content in your WordPress blog?  

One approach, which is foolish approach is to eliminate all these Sections from Blog, the reason why I say this as foolish approach because these all are the features of wordpress and due to these sections the user of your website can move anywhere, search any post, search post according to his interest and in response the bounce rate of your website will be significantly low. 

Second approach which is professional approach is to use all these Features (Categories, Archives, Tags) in your blog but don’t allow google to index them, if google will not index it then you are 100% safe. You can safe yourself by writing following php code in the header.php file of your wordpress 


if((is_home() && ($paged < 2 )) || is_single() || is_page()){
    echo '<meta name="robots" content="index,follow" />';
} else {
    echo '<meta name="robots" content="noindex,follow" />';

The best location to add this code snippet is just after <title> 

Hopefully you will find this tutorial very handy. Your comments are welcome.