My Fill Rate Keeps Changing and I Have Done Nothing
I know it might not seem correct if your fill rate statistic moves up or down and you have done nothing, or gotten no new orders on MusicStack, but that is all part of the only using the last 180 days worth of stats to calculate your fill rating.
It completely normal for your fill rate statistic to move up or down as data drops off the back end tail of the 180 days worth of data used in calculating your Fill Rate average. Just like it would be normal for your Fill Rate to go up or down if you marked orders today as SHIPPED or NOT AVAILABLE.
Fill Ratings are completely accurate as long as your mark your orders/items accurately. You can easily calculate this average to convince yourself:
To do this, if you take the number of SHIPPED ITEMS and divide that by the number of SHIPPED+NOT AVAILABLE items and you will end up with your Fill Rate percentage.
Stats are calculated on the last 180 days worth of items because this gives a buyer a more recent snapshot in time of how a seller has been doing on the system, over how they performed years ago.
Also, using a 180 day window average for Fill Rating statistics allows for a seller to improve (or not) on the system over time.
See also: Getting A Better Star Rating
See also: Seller Statistics
The Seller's Guide to MusicStack