You can build a pretty incredible business around the simplest ideas! This founder built an app for sending personalized digital greeting cards. Launched this year and it's already doing: > $52K revenue last month > $18K profit last month > 80% annual growth > 20,000+ customers > Bootstrapped All from helping people send better birthday cards, love letters and other messages. Love businesses like this. Now live on @acquiredotcom. Full listing:…