Maths: Work out a way to utilise free delayed payment in investment

I am building a website where 1 share is worth a fixed amount of 0.0001BTC. Every 3 hours the amount of shares doubles. So to start I have 1 share and in 3 hours I have 2 shares and 6 hours I have 4 shares as follows: 1 2 4 8 16 32 64 128 256 512 1024 2048 4096 8192 16384 32768 65536 131072 262144 524288 1,048,576 2,097,152 4,194,304 8,388,608 16,777,216 33,554,432 67,108,864 134,217,728 268,435,456 536,870,912 1,073,741,824 So I will start with 1 share and start selling half of my shares when I have 32 shares and keep 16 shares to the end to maximize my profits. When a user doubles or quad his amount of shares he can sell to next member in line to make a profit. This is what I need: *If I give members a loan or give them free access to share/s can they pay back a later date when they have earned money or taken out of profits...They will only profit when someone buys shares from them. Please show me a model on how this is best explained. *2nd option is to earn free shares. If they can go to bitcoin faucets that I recommend and earn sat 0.000001 each time they complete a task and 1 share is worth 0.0001 how would this effect my system because I have 1,073,741,824 shares that need to be sold in total *ultimately I need to find out the best way to sell all shares to other members so at the end of the process all shares are owned by members. Please work out the best way of how I can do this by making it as easy as possible for my members.