Why?This Will Verify your ownership of your Blog and Give you a professional look. So Displaying author Profile picture in Google Search Results will help you to get more traffic from Google...
But Google don't promise to add your picture to search result. also if you didn't do this you will not see it anyway. try it out.
How?First you must have a Google account and a "About Me " page on the blog , If you have Don't have, Create them quickly. And follow the steps.
1st Ad a link to your "About Me" page in the home page. (In a blog, you can add it to your sidebar or footer) Don't forget to add the rel="author" tag to the link finally your link will look something like this.
<a href="http://www.yourblog.com/about-me-page" rel="author"> About Me </a>
Then, Add a link to your Google profile (plus profile most likely) in your "About Me" page and add the rel="me" tag to it. after you have done the code will look like this
<a href="https://plus.google.com/your_plus_ID" rel="me" > Google Profile </a>
replace your_plus_ID with your Google (plus) profile ID . to find it and log in to your Google plus account and click profile tab. the you will see your ID in the address bar
That's all! now you have completed. Go to Rich snippet and search for your Site/Blog URL. If you have done this correctly then you will see a page like this. And if you didn't there will be some Error messages in red also you won't see your photo next to search result.
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