Well, I think the more accurate question to ask is: Is it a good delivery system for this book? In the case of YBF, at this point in the series life cycle it may very well be. In a general sense “Year’s Best” anthology numbers have been declining year to year, and in the particular case of YBF, over the last couple of years it’s been distributed by a small press, which almost certainly had an impact on the series distribution and sales numbers. At this point, a shakeup in the way things are done might be in order. That being the case, there are worse things than for this series to hook up with a young and hungry imprint which also happens to be nestled in the bosom of one of the planet’s largest publishing empires.
In a larger sense there are trade-offs. The first trade-off is that when you have a PoD book, at this point you’re writing off bookstores. I imagine one could special order the book from one’s favorite brick-and-mortar store, but on a practical level, the only way to get this book is to buy it online. As someone who has sold books primarily online before (most of my limited work through Subterranean Press, for example) I think it’s doable but it comes with implicit assumptions. In my case, the stuff I do with SubPress is primarily pitched to people who already know my work, not new readers. This fine because the runs are generally meant to be limited in scope. I think in the case of YBF, they’re also going to find themselves primarily pitched to people who are already fans (both in the sense of “SF/F Fandom” and “fans of the series”).
In the short run I don’t suspect it will be a problem; in the long run it may be. One of the reasons that offering stuff primarily to existing fans is not an issue for me is that I still have ScalziProduct™ in the bricks and mortar channel to reach new people, and that my personal presence online, via Whatever/Twitter/Facebook, is still generating new readers. I’m expanding my audience, in other words. YBF also has to do this. It has an engine for this in Tor.com, which I suspect strongly is still growing, but it will still be a challenge.
As for PoD in a general sense, at the moment I think it’s still primarily going to be a small volume business; with one or two exceptions the online sales channel is still tiny relative to the other places books sell through. It will almost certainly grow, although I don’t suspect my as much as some people suspect or possibly hope; I think in the long run most of the lunch PoD is eyeing is going get eaten by eBooks.
That said, for the right project, pitched to the right audience, a PoD book could do just fine. Perhaps YBF is that project.