Allowing visitors to comment on your blog's posts and articles is a great way to promote engagement while creating free, unique content in the process. Each time a visitor leaves a comment, it creates additional content for your blog -- content that search engines love. However, the downside to enabling visitor commenting is the potential for spam. Spammers will exploit this feature to promote their products, services and websites, all while watering down the quality of your blog. So, how do you identify and stop comment spam? Why Comment Spam is Bad Let's first go over the reasons why co...