It’s a more complex question that it sounds. Anime usually has multiple revenue streams, and none of those revenue streams are accurately reported to the public. A given anime might make money from the TV broadcast, DVD/BD sales, and merchandise, not to mention international licensing.

Add to that the fact that many anime can take years to break even and you get a perfect storm of never quite knowing just how well anything is really doing. There are ways to estimate, but no way to tell with accuracy.

SomeAniThing, a DVD/BD sales statistics aggregator for anime, uses industry charts from Oricon Inc. to compile sales data for anime week-to-week. Oricon receives their data from a list of retailers, so while the data they provide is trustworthy, it’s not necessarily complete. Nor does it take into account other revenue streams, or even international DVD and BD anime sales.

And the industry doesn’t have any real incentive to report concrete sales numbers either. Doing so can only hurt them in the long run. While it might make for good press to brag about numbers for a high-selling series, reporting the numbers for a flop doesn’t help anyone, and could in fact make a studio less attractive to production committees in the future.

Despite all this, however, fans have made efforts to gauge the success of anime, using what little data is available.