[Leanpub co-founder here.]

We use Markdown for authoring (one of two dialects: either Leanpub Flavoured Markdown or Markua).

We automatically produce PDF, EPUB, MOBI (what you were saying, essentially), but we also produce InDesign export. If you have a designer, give him/her the InDesign files. You can then produce exactly what you want as a finished product for print, with as much design as you want. But while the book is in-progress, nothing beats being able to click a button to publish.

...and if you don't want to do the InDesign work, you can just click a button and get a print-ready PDF file automatically produced by Leanpub.

Interesting. You should make that more obvious on the site.

I got the impression it was 100% opaque from web ui -> paying for printed books.

Do you offer paper size/weight options? And what are the prices if I already have the book proofed and am just looking for a press?

We don't produce print books. Instead, we generate a print-ready PDF or InDesign.

With the print-ready PDF, you can use it on unchanged places like Lulu or CreateSpace. (With the print-ready PDF, we alternate margins (wider in middle) and page numbers (put them on the outside), start chapters on the right, etc. We also omit the cover, so that you can use their cover wizard things.)

With InDesign, your designer will need to do some work. We produce ICML.

Leanpub is primarily an ebook production workflow + storefront. The print-book-ready file export is something we just give away, since our authors want it. We currently don't want to be in the business of producing physical books ourselves.

your opinion is your opinion, and i wouldn't call it "wrong".

but my opinion is quite different.

i've been active in the e-book sphere for a long time, and i've studied e-book authoring quite extensively, even programming some systems myself, and i think leanpub is quite good. i liked it better when you didn't have to make a lump-sum payment in advance, but even now, i think it's one of the best systems around, especially for people who don't want to code their own solution. and leanpub gives you access to a customer-base that's more than large enough to warrant the small percentage they skim off your sales.

you repeated what i said. it is perfect if what you want is to print github help pages as far as style is concerned. You just confirmed that this is what you want. The article we are commenting on is about artsy full color photos coffee table book, after all.