A logistic graph of European smartphone adoption, as an analogy for bitcoin adoptionMay be interesting to compare to smartphone adoption s-curve and the total population. Slope is likely to be similar from a technology adoption perspective. If you assume all fiat replaced then not sure 1M is enough.

When I began fitting a logistic model to bitcoin prices, I understood that adoption by speculators can occur much faster, i.e. steeper slope, than is the case for adoption of bitcoin as replacement of, and enhancement of, currency for transactions.