The best hackathons require a diversity of ideas. There are no bad ideas and no irrelevant sources. Let’s take the banking example, would you want your clients to keep griping about your horrible customer services on social media? How about you inviting couple of your most irritated customers to share their idea of good customer service, while you’re at it, have folks from your marketing team join in, bring in some of your call centre team members, invite a couple of people from your web design team, some client relationship managers, maybe even a former client or someone who has never done business with your bank, your could even throw in a couple of people from the finance department or may be even reps from the company that service your ATMs. Get the idea? There are no rules!