I almost wish Thor would drop like a rock just to get Fraction off it.
While that hasn't quite happened, Gillen saw higher sales gains over his run than Fraction has so far.
JMS' FINALE one shot sold at over 53.5k - Gillen's issue #604 jumped 15% above that to over 63k - which was less than JMS' issue #603, but not by very much. The peak of Gillen's run was #607 in Feb. 2010, that sold at almost 67k - higher than JMS' last issues. That was in the midst of ramp-up for SIEGE, however. After that, it saw many months of 5-7% sales drops as well as some occasional climbs, due to crossover or variant covers. Gillen's run ended at around 53.5k - right around where JMS' run ended, with less than about 55 copies difference.
Despite the promotion of Fraction/Ferry, issue #615 sold at under 52,900 copies - a fall of 1.2%. October's #616 sold at just barely over 51k - a higher drop. While Gillen had SIEGE to boost his sales, which Fraction doesn't, his name power hasn't been enough to stem the diminishing sales. I recall THOR winding up near 40k when it was canceled back in 2004, and it remains to be seen if it will return to such territory. It also is worth noting that quite a few of Gillen's early issues were sold at $2.99, which could have encouraged retailers to try it out. JMS' THOR was also sold at $2.99 an issue until #600.
For the first time in ages, not even CAPTAIN AMERICA can boast a 5 year sales gain anymore.
Sales rank are dependent upon the strength of the overall sales. While comics at the bottom of the Top 300 are selling better than years ago, there has been some weakness in the Top 100 for years. The #10 seller in October, KICK-ASS 2 #1, sold over 65,200 copies. 2-3 years ago, there is no way a comic under 66k would have been a Top 10 seller. It might have been lucky to crack the Top 20. In October, FABLES #99 just barely sold over 19,600 copies and made the Top 100; that was impossible even two years ago.