The argument that diversity in a medium benefits fans is a pretty simple one, which can be made several ways. From one angle, it’s good to have a lot of series selling well because then the medium is safe financially if one superhit series ends. From another angle, it’s good to have a lot of series selling well because that means the industry can experiment more, finding the sweet spots of niches that might fall through the cracks if the industry was mostly dependent on 10 or so series earning 80 percent of the total income. I mean, it’s good to have those sort of “carry the team” hits, but an industry solely dependent on established blockbusters is going to be in trouble when the big guy’s fuel tank runs dry if they don’t have some sort of farm system in place to generate another crop of them.

When a market has strong diversity, one of the ways it manifests is in a rapid turnover rate in bestseller lists from week to week; series in the top 10 one week will be quickly pushed aside by new releases. Particularly in front-loaded markets (i.e. ones where the majority of sales take place over the first 2-3 weeks of release), it’s a very discouraging sign when a given week’s slate can’t even beat the runoff from last week’s. Since manga is a market where the thresholds for charting are ridiculously high and hard numbers are almost totally unavailable outside of Japan, this turnover rate is one of the few ways we can start to compare the two markets.

I’ve written before about how the Japanese market for manga, with $5-7 prices, differs significantly US market for manga with $10-12 prices and a much smaller selection. It’s also no secret that the market for digital comics is different from the market for print ones. Viz representatives confirmed this on the record very recently when discussing increasing the price of a digital volume of manga from 5 to 7 dollars; “the crossover between print and digital readers is relatively small, and that many of our digital readers prefer digital editions exclusively.” Both Japan (Oricon) the US (NY Times) do have official weekly bestseller lists. Though the Oricon rankings go down 50 spots, the NY Times list is 10 series long each week, so I’m only comparing the top 10 slots. Additionally, reader andysislands has been kind enough to offer up his copies of the weekly Viz emanga store bestseller list (also 10 slots long), which is of extreme interest due to the professed lack of overlap because of print and digital markets.

What I actually did here was take each week’s bestselling manga list and recorded the number of new series making it on to each bestseller list. The full results can be found on this spreadsheet, and are plotted below:

The difference in turnover between the Oricon top 10 manga and the NYT top 10 manga is huge. Though any one week could show one with more than the other, the average NYT list contains about 2.96 new volumes, while the average Oricon ranking has 5.98 new volumes in its top 10. That’s literally over double the turnover rate. This gap suggests that manga in the US is dealing with some combination of two phenomena. One, manga sales in the US are very much not front-loaded. First volumes of series like Kuroshitsuji and Attack on Titan remain in the top 10 for 30-plus weeks or more; by contrast, the latest volume of most-popular-manga-ever-by-a-wide-margin One Piece only spent 10 weeks on the top 50. Second, the club of manga really capable of making waves in the US is a fairly exclusive one. Long tails are still tails, and the fact that the popularity of brand-new volumes of B-tier series can’t beat out volumes of A-tier ones that have been on the shelves for months says something about the relative scales each tier operates on.

The snapshot of the US digital market represents a sharp contrast to the print market. Each new weekly ranking from the Viz store contains an average of 6.70 new series, even more than the Oricon charts. This is in part due to rereleases of older series on the store, which come out as often as once a week and often end up charting. Which is kind of impressive; digital manga may have a reduced price per volume, but it’s a lot more expensive to spend 5 to 7 dollars 20 weeks in a row than it is to spend 10 to 12 dollars every 2 months. Also, while marking off series that appeared for multiple weeks, I never saw a series remain on the top 10 for more than a 6 week period, despite what one could assume is a reduced amount of competition resulting from the removal of Yen Press and Kodansha USA’s hit series from the charts.

I have a theory that might explain the differences between the two markets. US print customers tend to be more casual, supporting fewer series and taking more time to make purchases. Japanese and US digital customers tend to be more involved; those who want to buy a series seem to buy it quickly, and are more willing to make several purchases per month. The long-term health of these markets is a complicated topic well beyond the scope of this column, but this data supports the notion that digital distribution will be more than just a sideshow in the future of the US manga market.