Posted by TomCaultonThis post was originally in YouMoz, and was promoted to the main blog because it provides great value and interest to our community. The author's views are entirely his or her own and may not reflect the views of Moz, Inc.We all know building backlinks is one of the most important aspects of any successful SEO and digital marketing campaign. However, I believe there is an untapped resource out there for link building: finding your competitors' broken pages that have been linked to by ext...