When would this be useful? If your site has a blog with public commenting turned on, links within those comments could pass your reputation to pages that you may not be comfortable vouching for. Blog comment areas on pages are highly susceptible to comment spam. Nofollowing these user-added links ensures that you're not giving your page's hard-earned reputation to a spammy site.
At HubSpot, we talk a lot about inbound marketing as a really effective way to attract, engage, and delight customers online. But we still get a lot of questions from people all around the world about digital marketing. So, we decided to answer them. Click the links below to jump to each question, or keep reading to see how digital marketing is carries out today.