Recent comments on Dark Horse manga sales have been much talked about, and a post at Blogorama drew a response from Dark Horse Big Cheese Mike Richardson himself:

Saw these posts and had to respond. First, most of Dark Horse manga sells extremely well. While it is true that the horror line did not sell as well as expected, and that quality titles such as Eden and MPD Psycho are below expectations, most of our titles do quite nicely. Berserk. Ghost In the Shell, Blade of the Immortal, Trigun, Hellsing and others have all been big sellers and all of our manga continues to sell on backlist. The Lone Wolf & Cub series, by the way, has sold over 1 million copies to date.

More in the link. As Richardson points out, Dark Horse has been in the manga game since the very beginning, and they certainly have brought us some good reading. Also, Lone Wolf & Cub has sold more than 1 million copies. Via John Jakala, who has more Dark Horse manga facts.