Lady Gaga's album Born This Way has sold more than 1m copies during its first week of release in the US.

The album's opening haul of 1,108,000 copies is the best opening week performance since 50 Cent's The Massacre sold 1,141,000 in 2005. It makes Gaga only the fifth female artist to record a 1m-plus sales week.

Initial projections from Universal Music Group, Gaga's label, were modest at around 400,000. However, sales were boosted by AmazonMP3 selling the album at just 99 cents for two days last week. It is estimated that, of the final total, 440,000 sales were from the Amazon offer. Total download sales of 662,000 made it the biggest sales week for a digital album.

In the UK, Born This Way replaced Adele's 21 at No 1 with the biggest opening sales week of the year, outselling the entire top 10 combined.

The album was trailed by a campaign of almost unprecedented scale, including commerical tie-ins with brands including Starbucks to Google Chrome to Metro World News. Fans could even explore the unicorn and crystal-strewn GagaVille, a level on the Facebook game FarmVille.

Lady Gaga is currently working on the video for her single The Edge of Glory.