Kathy Sierra blogged recently about the Rails Guidebook, and along the way mentioned the loyalty that customers have toward the Pragmatic Bookshelf:

Let me put it this way, in an effort to support this young publishing company, loyal readers will often go to their site to buy direct -- which means paying more for the books than they'd pay on Amazon.

I won't argue with that; there is a lot of loyalty there. Dave and Andy are good friends of mine, and I certainly want to support their company by buying direct, and I encourage others to do so.

But it's not just loyalty. I would buy direct from them for a very practical reason, and last night I realized that it goes beyond even that -- I found myself wanting to buy a Pragmatic Bookshelf book that hasn't been written yet (and that, so far as I know, they aren't even planning) in preference to an existing best-of-class book. That's right; I prefer the Pragmatic Bookshelf book on a topic to a classic from another publisher, even when the Pragmatic Bookshelf version doesn't exist yet.

Why?

Because from the Pragmatic Programmers, I can buy a POPE -- a Plain Old PDF Ebook. Not tied to a special reader, or a single machine, so it's trouble-free. And it'll be on my laptop wherever I am, instead of sitting on a shelf at home somewhere.