It's time to renegotiate the deal with Cointerra. At this point 20% isn't going to cut it.
...?
Bitcoin difficulty adjusts every 2016 blocks. A block is mined about every 10 minutes. This means difficulty adjusts about every 2 weeks. There are about 4 weeks in a month.
http://bitcoindifficulty.com/
Bitcoin difficulty is adjusting about +1% per adjustment. Compounded monthly, this means about +2.01% increase per month.
Gaining 20% mining power per month, we are essentially realizing a real-value gain of about 18% per month as long as the chips are delayed.
I think 20% will cut it just fine.
Now on the other hand, if we can get a better deal I'm all for it
That website is way way off when it comes to next estimated difficulty.
http://bitcoinwisdom.com/bitcoin/difficulty
That one is way more accurate, and adjusts every so many blocks.
Our longterm average increase from the genesis block is 15.42% per adjustment. For easy math, lets say 15.42% every 2 weeks, thats 30.82% increase every month.
The increases as of the past year have been greater than this though. Reinvesting the 35% they are, will have them barely keeping up with difficulty, however, I do believe that it will have to level off eventually. I have no clue how large the network will be, but the larger the # the more it will take to push it higher.