The average Facebook user has 190 friends. If only one of your users share their scorecard and info about your course on their facebook page, then an average of 190 people will see. Multiply that by the number of users of your app and you get an impressive reach. Each time someone shares their scorecard or thoughts about your course, their friends will see a link to download your app. Then they'll tell their friends and so on. Your app, and your club will "go viral". You can imagine the reach your app will have!