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What do you do with ASIC and the historic cases which refute this claim?
Which ones are those?
Asicminer had increasing returns to scale for a while. Its growth outpaced the network even with sub100% reinvestment. I believe it's not the only case either although I would have to look around a bit.
ASICMINER was selling overpriced mining gear to ignorant/starry-eyed miners. It was mining with self-made chips and miners, and the competition at the time of greater-than-network-growth was nominal.
Yes, even now you can [theoretically] grow an operation faster than the network growth, up to [but not including] the point when you contribute 100% of the total hash rate. At that point, no amount of money will allow you to grow faster then the network.
Hope this helps.
@jimmothy re. "anyone who started mining before march has reached a positive ROI in both btc and usd":
wat