Retailer Brian Hibbs considers some problems with double-shipping that might not have struck you just yet:
One primary consideration is that every book, every where, (nearly) every time, suffers from what we generally refer to as “standard attrition” — that is to say that virtually every comic shows a slightly decreasing audience each and every month as readership walks away, or gets sidetracked. There are certainly ways to get bunches of new eyes looking at a book (crossovers used to do it… not so much any longer), and spike those numbers up again… but the general rule is a slow steady leak in all serialized entertainment.
What happens when you produce your comics twice a month is that the decreasing demand curve does nothing but accelerate because you’re giving readers more opportunities each month to “jump off”; and, in fact, you’re making it considerably easier TO jump off, because it is that much easier to get behind.
He also addresses the way in which an accelerated release schedule could penalize casual fans, the problem it presents for retailers looking to rack new releases, and a suggestion for why the idea that fans only buy comics “that count” may be the result of over-extending franchises in the first place. Well worth reading for anyone wondering about the shape of the current industry and the dangers of the future industry.