Bittorrent Sync is a great idea. But someone, somewhere is either going to reverse engineer this product and release it as Open Source, or they are going to develop something from scratch as Open Source. I huge portion of your users are concerned with privacy issues, and would consider such an offering superior. Given that you are no charging, there is little reason for you to not Open Source. You are just increasing your development costs.. Assuming there is a feature complete MVP available as Open Source, a substantial part of your community will leave. Instead, you should increase trust and shore up your community by going Open Source. If you do this right, this will only help you. Reddit is a great example of how you can release this way without losing anything. Thanks for the great product. -FT