The DCnU reboot/relaunch certainly led to a massive uptick in comic sales and DC sales as a whole. Comic sales were robust, DC ruled to comic landscape, and comics were suddenly being promoted in mainstream media.
But could that momentum be maintained? Could the bloom stay on the rose? Or would entropy set in?
While DC continued to lead the market, the lead over Marvel has shrunk. Certainly, there are some thing about the DCnU that worry me. The changes in creative teams feels like there was a lack of foresight, a lack of the big picture long term in these books. DC is already talking about cancelling some books ... cancelling after 3 issues of sales, without allowing a book to find its market ... seems like too quick a trigger finger.
As for Supergirl #3, sales dropped pretty dramatically. The issue sold about 10K less than the prior! That's a 17% loss. What could have driven that many people away. And it is a shame because I thought the third issue was the best of the book so far, less decompressed and with more moments revealing who this Kara is.
Of course, you need to put these things in perspective. If a year ago you asked me if I would be happy with Supergirl selling 45K, I would of course say yes. But I don't know what to think about this ... and I don't want to overthink it. A drop of 20% this early can't be considered a good thing.