When is a publisher a publisher?

When people in the UK reel of a list of small, or independent, presses I’ve never heard them mention The House of Murky Depths, yet we’ve published sixteen Murky Depths anthologies (and one at the printers as I write), three paperback novels (a fourth to be published later this year), five standalone comics and two hardback graphic novels. That’s 28 publications in our catalogue. So, can anyone tell me how many publications we need to get out there before we’re actually recognised as a publisher?