Or maybe Marvel fans are bigger gluttons for punishment than DC fans are, and the direct market (i.e. shops) have more faith in Marvel than DC. I am fascinated by the fact that DiDio over at DC has attempted to ape some of the "style" and actions of Joe Q's Marvel, and it's done nothing for DC but provide underwhelming sales. Marvel also has had more mainstream movie success to branch out, and their characters tend to appeal more to the older fan, who is the typical buyer of comics (as in a fan older than 18; few people younger read comics anymore in huge numbers, least Western ones).
I will say, though, that while I commend DC for attempting to starve off the "late comics" issue, interupting arcs with timely filler is backfiring. The reasonable solution would be to crack down a harder work ethic as well as waiting until stories are at least 3/4ths finished before publishing them (most fans would rather the first issue be late, even if that is the most embarassing for a company, and then the rest are on time, vs. the first 1-2 issues being timely and then every subsequent issue gets later, and later, and later). But, that makes too much sense, and so thus will never happen. On either side. Comics are a cottage industry, and that provides it some strengths and weaknesses.
Joe's done some good things, I'll give him that. I'd list them, but no one would really like to talk about them. But he almost cancels them out with "any fan can spot this, why can't a pro?" style blunders and Marvel just reaps in the profits. And I should note, a sales strategy of "one crossover event, year after year" was the 90's ploy. Just writing styles have changed to reflect the 21st century.