Yes BC have a bigger number, therefore more copies of sales to make up.
yes, we just gotten two weeks of sales for both since they both came out on the same day so not enough data,
Yes there are other factors,
But that is not the point!
the calculations are specifically for 10 days sales of the latest volume compared to a previous volume that also have 10 days of sales,
1 series have a positive VoV
another have a negative VoV
does that mean the positive series is doing better than the negative one? NO! NO! especially in absolute units!
you cannot even said the series with negative VoV is performing badly, you can implied it and give reasons as to why but you can't say it is performing badly which people here are not saying that, they just mention that there is an observable drop,
you kept saying where is the drop?
well BC17 sold less in 10 days than BC15 did in the same period of time, why? multiple of reasons, but it still ultimately sold less thus by definition a DROP in sales,
you can completely ignore KNY and it is still the same, the reason it was included because it had a positive VoV after 10 days even though it had a negative VoV for the 1st week.
You could mention that BC 17 sold more than BC 15 on its 2nd week therefore better legs
you could even mention BC17 more than doubled it sales from the first week(7day to 3 days though)
but you kept going denying people saying it dropped,
BC 17 could even eclipsed BC 15 in sales next week but it would not change the fact it still sold less in 10 days!
and don't try to include digital in this because the data is for physical and what is available for observation is that!
an opinion on sales discussion is not about what numbers are, that is fact!
if you want to give opinions it's on why it happen, what could happen next week and so on,
reasons doesn't change numbers, numbers give reasons.
I can't even...
why do I even do this, it just simple math, It can be forgiven if you can't read the chart, so I try to laid it out neatly, but that seem pointless on my part now, sorry to others because cluttering the thread.
100% Ichigo was my first romcom and romance and man, I was so sad that she won. I never had the same feeling again because of it but oh boy, how it hurt at the time. 
