NickDanger I must correct you because your statement regarding profit and difficulty being directly proportional is incorrect as this assumes a constant hash rate.  In fact profit is directly proportional to miner sales and hash rate (relating to difficulty) which is planned to grow with such a large portion of profit being reinvested and hardware bought at cost price.  What we can say about the difficulty factor is that it has the same effect on all miners from those using AM USB miners on their laptops to large industrial mining farms and not only ActM as your posts seems to suggest.

Sorry Jo if you were offend by my writing style.  I was often corrected when I was learning English for my 'lazy' style.  It's hard for me because I have to write quickly or I forget my point as I am translating to English and not thinking in it.  I hope this post is better.