However, since accepting the award from Jools Holland at the Grosvenor House Hotel in London last night, online retailer Amazon has reported a 1,190% sales increase for the album.
Let England Shake shot up to number two of the Amazon UK store bestseller list, while Mercury rival Adele retained her number one position with 21.
Watch Digital Spy interview the Mercury Prize nominees below:
"It's a great achievement in a year which has seen so many strong releases including the likes of Tinie Tempah and Adele whose albums have been massive sellers over the last 12 months," explained Paul Firth, head of music buying at Amazon UK.
"The Mercury Music Prize is an important award for any artist, new or established, and always has an immediate effect on sales. It will be interesting to see whether PJ Harvey will surpass Adele at the very top of the charts over the coming days."
Rob da Bank predicted PJ Harvey's win ahead of last night's award ceremony.