Our team is trying to understand and adapt Scrum and other agile practices, but we can not figure out how to deal with customer feedback when there is no customer. Every document about the subject emphasizes how important is having the customer involved in every sprint and how having early feedback helps correcting problems fast and maximizes satisfaction to both sides. I understand clearly this point.
In our case, we have no single customer. We develop a website and a smartphone app for an already established and growing audience. I am sure this is a fairly common case so I would like to know some real world experience about how to apply and manage Scrum in this case. Do you just decide all features by yourselves or do incorporate user testing in the sprint? Any other solution?