Collecting feedback from failed ideas is essential and can be done in a variety of ways, depending on the stage of idea development, the type of feedback needed, and the resources available. Surveys, interviews, focus groups, usability tests, and analytics are all common methods. For surveys, online tools like Google Forms or SurveyMonkey can be used to ask customers questions about their needs, preferences, pain points, and satisfaction with an idea. Interviews can be conducted one-on-one with customers by phone or video call to discuss their experience with an idea. Focus groups involve gathering a small group of customers or prospects to discuss an idea's benefits, features, and drawbacks. Usability tests involve observing how customers use a product or service and recording their actions and reactions. Finally, analytics tools like Google Analytics or Mixpanel can track data from a website, app, or platform to see how customers interact with an idea.