I have a soapbox topic for today.
It's always bugged me that cryptocurrency miners have thrown around the term "ROI" (Return On Investment) as a euphemism for getting their initial capital investments in hardware purchases. The correct term is "CR" or Capital Recovery.
When you see someone posting that they "got their ROI", or the "ROI on that GPU is 3 months", or "I've already ROIed so I'm hodling"... it makes them sound dumb. I realize that using ROI as a stand-in for CR is probably just miner slang now, but in my opinion, words matter. When you consider this is a forum where written words are the primary means of communicating ideas, then words matter.
Why is ROI an incorrect term? It's incorrect because ROI is a simple mathematical formula to quantify the ratio or percentage of gains or losses based upon your capital outlay or investment. You could have a negative ROI, but you don't really see anyone using that with the slang version of ROI used here. They treat "ROI" as an absolute number, when the terms they really should be using are "CR" or Capital Recovery.
A simple example of ROI is this: Miner A purchases a GPU for $1000, and over some period of time, that GPU mines $1000 worth of cryptocurrency. Miner A did not "achieve" ROI... because the ROI is ZERO! What did Miner A "achieve"? They achieved a 100% "CR" or Capital Recovery.
Now, let's look at Miner B. Miner B purchases a GPU for $1000, and over that same period of time, that GPU mines $1200 worth of cryptocurrency. Miner B also did not "achieve" ROI. The ROI is simply 20%. Their "CR" or Capital Recovery is still 100%. Both Miner A and B have "achieved" their CR, but their ROI is different.
Finally, let's look at Miner C. Miner C purchases a GPU for $1000, and over that same period of time, that GPU mines $800 worth of cryptocurrency. Miner C has an ROI of negative 20% (-20%), but their "CR" or Capital Recovery is still pretty good at 80%.
The above is a very simple comparison on why calculating "ROI" is not the same as CR. There are actually several other factors to calculating ROI. Time plays an important factor into calculating ROI, so it's never an apples-to-apples comparison unless all the same factors are considered. In the case of physical capital like mining hardware, you also have to factor in your potential resale value if you choose to exit mining at that point in time. It's rare to see anyone using ROI correctly, and it really has no meaning without all the proper context like time, resale value, and current coin pricing versus future coin pricing... so stop.
;TLDR
Simply put... stop using "ROI" when you mean "CR", as it makes you sound dumb.
I am actually a professional statistician, and I appreciate these points.