something like what Baxter said, im guessing, (yes, i said guessing. cuz everyone thinks and looks at things different ways). but the way that DC does things is that they don't have room to plan ahead.
heres the deal:
with Marvel, your able increase or decrease your order until about 3 weeks before it ships, thats the FOC or the Final Order Cutoff date. the last date to change your order.
with DC, your locked into your order about 3 months ahead of time, and you can't change it any way shape or form, cuz you don't know how the market is going to do.
for example...you have issue number one of the comic called......"SUPERPOWER" and this is being published by both Marvel and DC, the issue doesn't come out til march, but you have to place an order in January...this being a brand new series, you don't know how it is going to do, weather people will like it or hate it, so you only order in a few copies. and your locked in.
Marvel: you notice that this seems to be getting a really good hype going, and its before the FOC date so you increase the amount of copies that you have coming in, this creates more on hand supplies limiting the amount of reprints, and more people are able to get there hands on the issue as there are more now on the market.
DC: you notice that this comic is getting a good amount of hype, but there is nothing you can until it comes out, and the demand is so high that it sells out. when it goes back for a reprint it takes about 3 weeks and the readers that wanted to read this have now moved on...