Valkyrie: Jane Foster #1 - 42,948 (#39 in units, #56 in dollars)
Valkyrie: Jane Foster #2 - 43,640 (#35 in units, #72 in dollars)
Valkyrie: Jane Foster #3 - 39,564 (#42 in units, #73 in dollars)
Valkyrie: Jane Foster #4 - 23,686 (#106 in units, #118 in dollars)
Loki #1 - 51,725 (#25 in units, #64 in dollars)
Loki #2 - 22,944 (#92 in units, #98 in dollars)
Loki #3 - 17,493 (#129 in units, #129 in dollars)
Loki #4 - 19,517 (#135 in units, #145 in dollars)
Valkyrie was obviously doing better. Issue #4 took a fall, but it's possible the first 3 issues were enough to get it renewed for another arc. Also, keep in mind that Jane has the success of her Thor run to back her up. If that book continue to smash in trades (for instance, the Goddess Of Thunder volume is still on the first page of the Amazon bestsellers), Marvel might see this as an incentive to keep publishing more Jane Foster books.