Well, if your blog is self-hosted on a shared server or dedicated, you are always need to set up the robots.txt and make sure the search engine is crawling your site without any issues. I am not talking about blog hosted at blogspot.com, wordpress.com or other blogging platform.

You will need a robots.txt when you have buy a hosting package from hosting company. Although this is not necessary to learn by blogger but it is an alternative knowledge which you can improve your blog SEO with better optimization.

AskApache.com comes out with a good and simple listing on how to work with robots.txt such as what can be added into robots.txt. Setting up your robots.txt is recommended only when you are facing bandwidth issue or search engine crawling issue. Otherwise, it is advisable not to modified the existing robots.txt when you have a blog that runs smoothly already without any problem.

Go to AshApache.com for a better description on how to improve SEO with robots.txt for new blog or existing blog.