Do… do I have to talk about this? There are not really any talking points to be said here, Oricon have Kimetsu known number at 12.05M version this article 10.8M, which even if oricon overestimate, it would have made no sense. But, I’ll still try to argue otherwise.
(note: edited paragraph)
While Oricon full method are not exactly known 100%, they have never claimed to be total sales source, but only domestic estimates based on the stores their tracked. I mentioned above that they used POS as the main source, which I would suggest further reading own your own. But my point is that their estimates are… estimates. Hopefully their methodology is a consistent fair one and is used throughout for everything. In theory, depending on how the volumes are distributed to stores, if multipliers are used, it can cause some series to be overstated, i.e. more Kimetsu sent to bookstores compared to convenience stores or web stores. Even then, a 1.7M discrepancy is too much and in my opinion is unlikely.
Add to the fact of constant report of kimetsu being out of stock and the constant reprint orders, the 12.05M actually fit a lot more with the circulation numbers
Kimetsu oricon total at 14.72 which ties in pretty good with the 16M number