Competitive Analysis.

Data on what works well or poorly on other sites saves you from implementing useless features and guides UX investments to features that your users need.

How to Conduct and Prepare a Competitive AnalysisEdward Lowe FoundationJune 18th, 2019
Competitive Analysis DefinitionEntrepreneurJune 18th, 2019
Competitive Usability Evaluations: Learning from Your CompetitionNielsen Norman GroupDecember 15th, 2013
Competitive Analysis ExampleAdventures in UX - Amelia BauerlyJanuary 1st, 2013
Competitive Analysis: Understanding the Market ContextBoxes and ArrowsFebruary 27th, 2006