Most companies do not discuss sales figures in public, unless they can use it as advertising. So you will only hear about the mega successes, such as when Manga's initial Naruto releases broke five figures. It's giving too much information to the competition for one thing, and it does affect how your company is perceived.
I have seen projected sales figures for anime, and considering that Revelation doesn't sell anime any more in the UK, I guess it's OK to mention it now. You have to put into context though, Revelation never really had the market impact that Manga, MVM or ADV had, certainly didn't have the advertising to really push their titles.
When I got their review discs, they were pretty much alone in sending out internal projected sales figures with their discs, no other company does that, and I guess it was to save on doubling up on printed PR material.
When they released
Tsubasa V5, they expected to sell 1000 units in month 1
School Rumble V3 750 units
Peach Girl V5 500 units
Mushi-shi V5 500 units
FMA Alchemist The Movie LE 5400 units
That's what they wanted to achieve. The fact that Funimation pulled their deal and contracted with Manga instead indicates that they didn't achieve their aims.
One concrete sales figure that I did have from them states that they sold 740 units of Full Metal Alchemist Season 1 Part 1 in just the first week, indicating that they had some success with their boxsets.
Anecdotally, it seems that when the contract for Funi product switched from MVM to Revelation in the middle of FMA's run, the sales of the FMA single volumes plummeted, because few people knew that Revelation were still releasing them.
Also anecdotally, we hear tell that Blu-ray requires 3000 sales to break even. A few years ago, with DVD it would have been 1000 sales, although I guess that figure might be lower now.
A killer anime title, like the initial Naruto boxsets hit trade headlines when they break five figures in sales. From that we can expect the average anime title to indicate success when they break four figures. 1000 sales for a show on DVD is a success.
At the other end of the scale, we do hear about utter failures. When ADV were circling the drain, they did mention that some single volume discs, like Red Garden and Wallflower sold a few tens of copies.
It's important to note that with most companies now, it's the initial sales figures that matter, that inform their decisions. It's what a show does in the first month, or even the first week that is important. What a show does over the lifetime of its release is less important. The initial release will see profit for the company, even with the pre-release discount. When e-tailers start putting discs in bargain buckets and clearance sales, not so much.
And with the death of the high street, it's become apparent that not even week 1 matters anymore. It's preorders that are counted, as became apparent with the Casshern Sins Blu debacle.
Remember that Blu needs around 3000 just to break even. My guess is that pre-orders for Casshern Sins Part 1 on Blu may have only been in the low three figures, or less. If pre-orders had been closer to 1000, I personally wouldn't have been so hasty to cancel it. The sales for that must have been an utter disaster, although that is only my opinion and conjecture.
You certainly don't publish those sales figures.
But if we take the figures of 1000 for a successful DVD, and 3000 for a successful Blu-ray as gospel, then Manga's intimation of 10000 disc-buying fans in the UK seems very conservative. After all, not every fan buys every series, and 10,000 implies that each fan has 10% of market output on their shelves. That's actually a whole lot of anime, four or five new titles a year. I'd say that casual fans who buy the occasional anime probably increase that number significantly, maybe 20 - 25,000. Of course there are the hardcore forumites who'll buy everything that comes out. I'd say that's a few hundred people, the ones that complain when a series is cancelled mid-run, but as previously stated, a few hundred isn't enough to sustain an industry.
Of course everyone wants to be Optimum Releasing. Their Ghibli discs push 6 figures easy, supreme titles like Spirited Away may even have pushed past that to Hollywood blockbuster levels, a few hundred thousand.
Incidentally, prior to Avatar, the biggest selling DVD in the UK was
Mamma Mia, which sold 1.7 million on day one of release. The average mainstream blockbuster title sells a few hundred thousand copies on initial release.
That makes five figures for Naruto, a niche interest title, look f***ing amazing, and why four figures for the average anime DVD is pretty healthy.