OOPS. She shouldn’t have done it again.

A week after tickets went on sale for Britney Spears’ Domination concert series at the Park MGM in Las Vegas — fresh on the heels of a year-long Vegas stint that ended last December — her first month of shows remains more than half unsold, sources told the New York Post.

By comparison, a 27-show stint for Lady Gaga that begins on December 28 at the same venue nearly sold out in the first week tickets were available.

And an Aerosmith residency that starts on April 6 was 85 per cent sold out in a week, according to sources.

It was only last New Year’s Eve that the Toxic singer wrapped up her initial Las Vegas residency — a four-year, 248-show run at Planet Hollywood entitled “Piece of Me” — which with a $138 million gross ($A191 million) has her in fourth place on Las Vegas’ residency register.

Celine Dion leads the list with $385 million ($A534 million) for her 717-show A New Day series (2003-2007), followed by the same artist’s $233 million ($A323 million) take for her 399 Celine dates (2011-2019), according to Billboard.

Elton John’s extended Red Piano stay (2004-2009) ranks third, with $169 million ($A234 million).

Spears is launching the Domination series on February 13, despite the fact that Piece of Me stopped selling out after its first two years in Las Vegas, an insider said.

The series was announced on October 18 — less than a month after it was reported that 36-year-old Spears will have to pay thousands of dollars more a month in child support to ex Kevin Federline.

Meanwhile, Gaga and Aerosmith stand to benefit by being residency newbies.

Gaga’s critically acclaimed starring role in A Star is Born has her popularity at an all-time high, a source said. And Aerosmith and its boomer following have reached an age where both want to see each other while they still can.

The venue for all three residencies is the Park Theatre — a 5200-seat venue at the Park MGM.

Gaga announced her 27-show run on August 13 while Aerosmith went public with its 18 dates on August 24. Spears revealed her new 32-concert series on October 26.