Guest blogging can help build authority in your industry and is done very successfully by many of the larger brands. There are three main reasons as to why you may want to undertake guest blogging. It may be that you want to get your name recognised as an expert within a certain industry, you may wish to get traffic back to your website through the blog posts or you may want to simple earn backlinks to your site to help with your SEO. Ideally, you want to aim to do all three of the above in your posts. If you are just trying to build up authority or get traffic to your site you will need to find popular, well-known blogs in which you can post. If you mainly want to get backlinks then you need to carefully research the sites that you are posting on, such as their domain authority. There are many tools online that will allow you to look into the background of a certain domain and find out the facts you need to, to find the best sites to post on. You should always find relevant blogs to post on, so for example, if you sell computer equipment, make sure you are posting on technology or IT blog sites.