http://www.icv2.com/articles/news/1850.html
Of all the top 100 comics sales, DC alone for August here is how she rank:
1 1 221.48 JUSTICE LEAGUE O/AMERICA #1* $3.99 DC
5 10 124.51 52 WEEK #13 $2.50 DC
6 11 124.41 52 WEEK #15 $2.50 DC
7 13 123.21 52 WEEK #14 $2.50 DC
8 14 122.39 52 WEEK #16 $2.50 DC
9 15 121.52 52 WEEK #17 $2.50 DC
11 8 114.34 ALL STAR SUPERMAN #5 $2.99 DC
13 3 111.34 JUSTICE #7 (Of 12) $3.50 DC
15 17 100 BATMAN #656 $2.99 DC
16 19 94.46 SUPERMAN BATMAN #29 $2.99 DC
19 23 88.16 WONDER WOMAN #2 $2.99 DC
27 31 77.36 SUPERGIRL #9 $2.99 DC
30 32 73.59 FLASH FASTEST MAN ALIVE #3 $2.99 DC
32 34 72.13 TEEN TITANS #38 $2.99 DC
35 37 69.78 SUPERMAN #655 $2.99 DC
36 38 69.15 DETECTIVE COMICS #822 $2.99 DC
43 43 60.39 ACTION COMICS #842 $2.99 DC
46 47 53.64 GREEN LANTERN CORPS #3 $2.99 DC
48 49 52.74 TRIALS O/SHAZAM #1 (Of 12) $2.99 DC
51 52 47.68 ION #5 (Of 12) $2.99 DC
54 55 46.37 SECRET SIX #3 (Of 6) $2.99 DC
55 56 43.77 OMAC #2 (Of 8) $2.99 DC
56 57 42.99 MARTIAN MANHUNTER #1 (Of 8) $2.99 DC
57 58 42.22 OUTSIDERS #39 $2.99 DC
59 60 41.79 NIGHTWING #123 $2.99 DC
61 61 41.52 SUPERGIRL & LOSH #21 $2.99 DC
62 62 39.84 ALL NEW ATOM #2 $2.99 DC
65 65 38.14 ROBIN #153 $2.99 DC
67 67 37.2 GREEN ARROW #65 $2.99 DC
71 72 34.78 SHADOWPACT #4 $2.99 DC
72 73 34.57 BLUE BEETLE #6 $2.99 DC
73 74 33.66 JSA CLASSIFIED #15 $2.99 DC
74 75 33.52 JSA CLASSIFIED #16 $2.99 DC
75 76 32.96 BOYS #1 (MR) $2.99 DC
76 77 32.94 UNCLE SAM & FREEDOM FIGHTERS #2 (Of 8) $2.99 DC
77 78 32.9 BIRDS O/PREY #97 $2.99 DC
78 79 32.85 CREEPER #1 (Of 6) $2.99 DC
79 80 32.56 CHECKMATE #5 $2.99 DC
81 69 30.39 BATMAN & MAD MONK #1 (Of 6) $3.50 DC
86 88 28.98 JLA CLASSIFIED #26 $2.99 DC
88 93 27.68 CATWOMAN #58 $2.99 DC
90 94 27.26 BOYS #2 (MR) $2.99 DC
91 96 26.91 Y THE LAST MAN #48 (MR) $2.99 DC
92 97 26.44 FABLES #52 (MR) $2.99 DC
96 100 25.11 BATMAN LEGENDS O/T DARK KNIGHT #209 $2.99 DC
97 101 24.88 HAWKGIRL #55 $2.99 DC
98 102 24.54 JACK O/FABLES #2 (MR) $2.99 DC
100 104 22.9 DEADMAN #1 (MR) $2.99 DC
Take out the 52 weekly comics and Supergirl is a top 10 sales DC comic book for all the months her comic book has come out.