Talk about contributing to the public health problem in our ERs. Emergency medicine in the US is in a horrible state. Overcrowding is one of the primary reasons. See: http://www.ama-assn.org/amednews/2009/01/19/prsb0119.htm One of the primary reasons for the large influx of patients is the diversion of primary care visits into the ER for non-urgent matters. A booking system that encourages non-urgent care visits to t…
If you want to solve the ER overcrowding problem, you should do it directly, by adding a surcharge (over and above the one that already exists) for nonessential ER visits. There's no rational reason to force people to sit in a crowded ER waiting room.
Meanwhile, a retail interface to the ER scheduling systems that already exist is more likely to help than hurt overcrowding, because it will route patients to the least crowded ER in their area.