People have long added external links to their blogs in hopes of being seen as relevant. “What will happen if I external link to a popular website like Wikipedia?” a Redditor asked. Many people in the industry follow this practice, and there have even been some case studies proving the validity of claims that external links on your site can help with rankings. The sites that had external links did experience a positive impact from the links. However, if you heed Google’s advice, this is Mueller's latest and greatest information on using external links on your blog posts.