As of Monday, Bo's first "Idol" single — which includes the songs "Inside Your Heaven" and "Vehicle" — was ranked No. 1 on the Barnes & Noble best-seller list.
Watch Underwood Wednesday morning at 8:52 a.m. EDT on "FOX and Friends."
What is more impressive is that the CD will not even be available until late July.
He was ranked No. 1 based on pre-release orders.
Carrie — whose single also includes "Inside Your Heaven" and a new song, "Independence Day" — had drawn only enough early orders to rank No. 16 this weekend.
Both singles are songs the two finalists sang in their showdown last Wednesday night.
The sales seem to confirm what guest "Idol" judge Clive Davis, the head of RCA Records in the U.S., which has the rights to sign "Idol" winners and runners-up, seemed to say about Bo's appeal to record buyers.
During the finale, he said Bo had the makings of "a million seller."
The Idols' "Showstoppers" CD, meanwhile, is also a hit, ranked No. 10.