[floozyspeak]

The biggest reason to have an app is to be seen in the network, to be there when users go to search and try and something new. The next best reason, plays more to your ego, gives you internal drive to do more, learn something new and feel like you've made progress, it may be serious fail material but it's still more than a website. Third, transactional goodness is a mere click away vs create an account and enter credit card here, if you nail the concept and yes share the funds with the store you stand to reap the rewards.