Abstract: Systems and methods for detecting and analyzing changes in backlink activity over a period of time are disclosed. For example, the backlinks to web-based content and websites of an entity and/or a competitor of the entity may be monitored over time and changes in the backlinks over time may be determined. Comparison of backlink activity over time may be used to evaluate the backlinks of the competitor to ascertain, group, or otherwise categorize or rank the reasonableness and level of authenticity and actual content value of the backlinks themselves and to determine whether such backlinks are likely to be “black hat” backlinks subject to penalization by search engines.