In 2012, Marvel called on Jason Aaron to revamp the Thor series. With his success in relaunching Wolverine (with Wolverine: Weapon X) and The Incredible Hulk, the writer of the critically acclaimed series Scalped worked his magic on Thor: God of Thunder, a series that presented the Odinson in a new light, including an opening arc that featured three different Thors (past, present, and future) at the same damn time. Aaron kept the overall tone of Thor in tact, which bringing him all across the world tree, and beyond.
Post Marvel's Original Sin event (which Aaron also wrote), the Odinson was no longer worthy to hold the mighty hammer Mjolnir, and a new Thor took his place—a female Thor. And while Aaron's Thor: God of Thunder did well, sales-wise (we're talking 110K copies of Thor: God of Thunder #1 being sold), this new Thor series is kicking its ass.
As The Verge notes, 150,862 copies of Thor #1 were sold, which is an increase of 36 percent. What's interesting is that the following issues of each title, while selling less, show a similar trend, with the new Thor series selling 30 percent more than the Thor: God of Thunder series. Understanding that is simple math; the first issue of most high-profile Marvel characters seem to do very well, and the hype surrounding this all-new female Thor has been off the charts.
Right now, the data doesn't really show why this is happening; Fusion's stats on this particular Thor trend don't give any kind of demographic information, so it's hard to say exactly what the reasoning for the increase is at this point. One key might be the fact that the "big reveal" on who this female Thor is hasn't happened yet. There have been a few strong hints, but as of right now, many in Asgard are trying to figure out who this mysterious woman is.
Is there a chance that, after this reveal, sales might dip? Who knows. All we know is that this new Thor is kicking the old Thor's ass, and it should give comic book readers hope for a future where more female characters are given stronger roles.