Responsible for: paying* + coordinating the people who get produce the product (this includes the author herself, the designers providing art, the person doing the layout, the editor, and the printer - down to helping the authors choose paper stock); distributing the product - we do direct sales, as well as have the contract with PGW, a distributor, that lets us get into bookstores (sad but true, we had to get one before Barnes and Noble would stock xkcd: volume 0); we have a warehouse in Austin (Hi Amplifier!) that handles all the fulfillment for kickstarter rewards, we manage that relationship to make sure every address-change is accounted for and everyone gets their perks; in the case of this kickstarter, we're also the ones coordinating with manufacturers to make everything from bookmarks to plushie-skulls; we do a wee bit of promotion, but that's how we can afford to give authors (75%+) of the profits -- they already bring their fans with them.
This is a bit old, but still pretty accurate -- I published a step-by-step guide to do what breadpig does, so anyone can replicate it, because that's how we roll.
Sorry for the mega post but I know how much work Christina (runs breadpig ops) put into pulling this off and I feel like an article that doesn't even mention that isn't doing it justice. Obviously the story here is Ryan, which made this amazing thing possible, and he deserves 99.9% of the credit for the product and campaign, but it's not quite as simple as "self-published."
*We paid for printing up-front with xkcd's book and a couple of SMBC's, but thankfully kickstarter came along and we've since adapted the business because we now have the pre-order dollars from backers.
I always thought the publisher was the person who organised actually making and distributing the media (book in this case). I don't think they have to pay for it to be made.
I define it as paying for production, and distributing the product..