I love the way that The New Yorker is using the iPad to construct a whole new revenue stream from its back issues.

It started with “At the Ballpark”, an iPad-only collection of New Yorker baseball writing from 1929 to 2011, featuring the likes of John Updike, David Grann, and of course Roger Angell. That was sponsored by United Airlines.

The baseball collection was followed by a golf collection (Ogden Nash, Larry David, United Airlines again), and now by a “sustainability” collection sponsored by BMW and featuring the likes of John McPhee and Michel Specter.

Nearly all of these pieces are timeless, just waiting to be rediscovered. And the New Yorker’s archives are so deep, and are of such high quality, that there’s really no limit to how many of these things it can produce. Each one is very cheap to put out — just cobble together a bunch of articles under a theme, and get a TNY writer to pen a short introduction. Meanwhile, the advertisers get to align themselves with popular or trendy subjects (golf, “sustainability”), and reach an audience which is affluent even by New Yorker standards.

I’m in the process right now of helping to put together a printed anthology of business writing, from many different sources; such compilations can be very good, but they’re also a lot of work to put together, in terms of securing permissions and going through the laborious process of collating, printing, and distributing physical books. The New Yorker’s special iPad editions piggyback on the existing New Yorker iPad app, and are therefore very lightweight, with a marginal cost which is tiny in comparison to TNY’s printed compliations. What’s more, instead of persuading thousands of individual book buyers to shell out cash for books, the sales job on the iPad editions is much easier: you just need to persuade a single corporation to buy a single sponsorship.

TNY has experimented with selling digital compilations, too — its 9/11 e-book is $7.99. And the more different models and revenue streams, the better. But the small sponsored collections are for me the most exciting, from a business-model perspective. It’s hard to sell old content — but it’s much easier to repackage it and get a sponsor to pay you to do so.

Felix Salmon is an Audit contributor. He's also the finance blogger for Reuters; this post can also be found at Reuters.com.