Your maths is misleading at best.
Misleading? This is a speculation thread, BTCGARDEN has stated their plans, I am using them as a guide to speculate. I would say they are optimistic. I'll go ahead and respond to your points so you know where I am coming from. I am in no way attempting to be argumentative, I'm just justifying my views.
First, 'scaling it back' to 4000 is a poor representation of total bitcoins/day. The average is more accurately described as 3600/day.
The system is designed to release a block every 10 minutes and therefore 6 blocks an hour and 144 blocks a day. Each block is worth 25 bitcoins.
144 * 25 = 3600
More like 25,000/week
You would only be correct if the overall network hashrate was flat. It has not been flat, it has not even been linear, it's been on an exponential growth path. 4000btc per day was the least optimistic number I posted. I would bet 1btc that the real average daily btc mined continues to be ABOVE 4000.
http://blockchain.info/statshttp://blockchain.info/charts/hash-rateSecond:
Hitting a hash rate target of 35% is questionable - a big feat indeed. As is calculating ROI by assuming BTCGarden could hold 35% from September 'til the end of December given what else is going on in the landscape.
You're assuming:
a) knc doesn't deliver any meaningful volume
b) actm doesn't deliver any meaningful volume
c) asicminer doesn't scale anytime soon
d) pico doesn't get its 100TH up
e) bitfury doesn't deliver any meaningful volume
f) cointerra falls flat
g) avalon chips never arrive
h) terrahash?
Bottom line: You won't be making 85% by December. I don't even know if you'd make 50%
a) I'll posit that knc delivers in mid October after a modest 3 week delay, and starts hosting at the beginning of October. Due to the delay and refund policy, I'd guess they will refund around %50 of their orders as the mining rigs most likely won't achieve ROI (
http://mining.thegenesisblock.com/ has previous 30 day difficulty increase at 75%). Why would someone keep a pre-order for a device when refunding would make them more money?
b) ACTM's earliest estimate for delivery is the END of October. Mid-November is more realistic for devices to start showing up on our door step.
c) AM appears to self regulate their growth to <20%. Their stated network target is to maintain 10% of the overall network. I've been watching them closely (as have many) and don't expect them to push the network due to perceived effect it would have on hardware sales.
d) 100TH will most likely slowly increase hasrate and achieve 100TH by the end of September
e) bitfury only really sells in Russia and won't really start impacting the network until mid October
f) cointerra has no hope of delivering before December. For the purposes of this discussion they are a non-issue.
g) Even if avalon got their $#!7 together that's what 40TH?
h) terrahash?
Optimistically none of the above will appreciably be in place in September, October will be a huge month and the network will continue to increase to 2000TH by the end of December.
This will give BTCGARDEN a chance at %35 -%16 over the stated time range before adding their second batch of mining equipment. Making my dividend potential estimate possible. (though admittedly optimistic)
edit...
For those not reading my previous post, I'm speculating that we could receive up to 85% of our IPO price in dividends by the end of the year. Even if I'm way off and we only receive %50 in the next 4 months, that's still an incredible return.