While there is an ongoing discussion of whether a mistake is likely in the monthly Diamond Sales Charts in the comments of the DC sales charts, statistics guru John Jackson Miller passes along an information-packed column that reveals that there WAS at least one mistake in November’s charts from Diamond:

Running and re-running my calculations on the Top 300s, I became increasingly convinced that Diamond had transposed the columns for units and dollars in its table when it reported those percentage changes in November. As released, the table showed comic units down 5% and dollars down 10% year-to-year— which I realized was probably impossible, given that the average cover price of comics ordered jumped to its highest level in history in November. Diamond’s Dan Manser confirmed to me yesterday that the columns had, indeed, been accidentally transposed; I have made the corrections everywhere those figures appear on the site.

The table is extremely complicated, so it’s not a hard mistake to make at all; I realized today that I had flip-flopped unit and dollar market shares last month, myself — although just on the website, not in my calculations. (That has also been corrected.) Ultimately, the revision is very much good news because it means that overall dollar orders for comic books and trade paperbacks were actually up by less than a percent — as opposed to down the originally reported 8%, which was really the case for units. Trade paperback sales, helped by Walking Dead, were sufficient to recover the ground lost by comics in dollars.

Miller has also temporarily halted attempts to use Diamond’s new year-to-year and month-to-month stats to guess the size of comics long tail; there are too many variables for it to be accurate for now.

His revised November sales can be found here. Chart watchers will have a ball with this one.