The sales numbers for January have been released and overall it was a good month for comics. Sales were up and Marvel, in particular, continued to ride high on their rolling reboot. As usual, ICv2 is the site I go to for my numbers. Here is the link to their top 300: http://www.icv2.com/articles/news/25024.html
As for Supergirl and the other Super-titles, I would say the news isn't that good. The thing is that the books should be riding high right now. They are in the midst of the first super-crossover in the New 52. And Grant Morrison is bringing some energy to the ending of his Action Comics run.
Unfortunately, I think the H'El on Earth has been fairly lackluster. Sure there has been a lot of noise and action. But the story hasn't wowed me. H'El remains inscrutable. Supergirl has been played as the hysterical, gullible, lovesick fool. Superboy has been impressed and unimpressed by Superman simultaneously it seems. And Superman, of all of them, isn't exactly showing super-intelligence. He has left Supergirl hanging out to dry, not giving her the information she needs, and acting rather tempestuous.
Not surprisingly, there has been no bump in sales for any of the titles.
Supergirl #16 had the bonus of guest starring the Justice League and showcasing the Flash. In this story, Supergirl remains oblivious to the galactic carnage that H'El is planning. And The Flash decides that it makes more sense to wrestle her or find and fire a weapon at her than to tell her that H'El plans to implode our sun. Sooo ... not too good. Thankfully, Mike Johnson has her say the right thing.
Despite the guest stars and the crossover, Supergirl tread water in sales. I suppose I should be happy that there wasn't further erosion on the title. Supergirl #16 ranked 69th overall (the book was 70th last month) and sales went down by only about 500 issues.
In the end, Supergirl is no where near the danger zone. But certainly her behavior in this arc has to be considered a low point for the character since her debut in the New 52. Hopefully the loyal Supergirl fans will stick around to see if the new creative team is able to elevate the character from these doldrums.
I will add that it is interesting to review the lower selling books given the announcements of the canceled books. Still hidden down there in the weeds and not canceled are Legion of Super-Heroes and Demon Knights. I hope DC lets these books breathe a bit.