After thinking about the Christian Science Monitor’s plan, the most puzzling part is the (non-free, price TBA) daily PDF edition, delivered over email. PDF editions have always felt to me like a poorly reasoned set of training wheels for the transition online. They look like familiar print editions, and they speak the same design language, so they add a degree of comfort to editors and publishers moving away from dead trees. But I don’t know of a single successful example anywhere of a PDF-based subscription news product succeeding. PDFs are great for printing but awkward for onscreen reading.

And people don’t print them. As Joel Kramer put it when MinnPost.com canceled their PDF edition in July:

Beginning today, we’re dropping the MinnPost in Print feature. Readers will continue to be able to print stories from the site. But as more and more of you are reading MinnPost online, we found too few readers were using MinnPost in Print to justify continuing putting together a printable summary of the site.

A straightforward email newsletter with links back to pages on csmonitor.com makes a lot more sense to me. Presumably the Monitor is betting their older readers will print out the PDF each morning, but won’t even they eventually figure out they can just go to the web site and see the same stories for free?

One other point. I see some, like the very sharp Rick Edmonds, comparing the Monitor’s model to Politico, which also prints a paper edition (three times a week in their case) to go along with their web site. Rick refers to the print edition in this model as a “supplement” and a “residual” product.

But it’s important to note that, in Politico’s case, print is not the supplement, financially — it’s the main moneymaker. As Jim VandeHei told AJR a while back, a full 60 percent of Politico’s revenues come from their 27,000-circ thrice-weekly newspaper. That means only 40 percent of their revenues are derived from their huge online audience (3.5 million unique visitors in May, no doubt much higher now).

Do the math: In revenue terms, that means a print reader is worth about 200 times what a unique visitor is online. Print is by no means residual in these models; it’s still the chief revenue source.