My thoughts: It's unthinkable to charge a fee from every user.If I pay for my shares, I have to be able to share them with free users and they must get those advanced features when accessing my folders. Don't restrict my usage just because my customers/friends/family don't have upgraded versions. You must charge ever user that wishes to CREATE advanced folders, but not every user that wishes to ACCESS them. This is important!U$ 40,00 a year per user doesn't work. Make it a monthly payment of U$ 4,00/month and give the home user the option to go yearly for U$ 20-25 a year. Then, charge more if more than 5 different users need access to the folders (company environment) upping it to U$ 40,00/year.Why? This makes it easy to understand, transparent, and accessible for personal use. Your objective here should be: Don't restrict personal users, give them a cheaper version to pay for and get all features. Or you will end up with just a bunch of free users complaining about the high price and no one will pay for it because it is not popular. I am a private user, and I wish to pay, but make it reasonable.If you follow these tips, I will be totally open to paying a fee, but make it reasonable. Notice that spotify/Netflix charge users 5-10 U$ a month for development, hosting, streaming, AND all the costs for the content, so my pricing model should be more than reasonable.