One quarter of Mercury prize finalists have sold fewer than 1,000 albums in the UK since being nominated for the award. Despite the Mercury’s reputation as a career-maker, several of this year’s lesser-known nominees have seen a sales bump of only 500-800 copies.

Data provided by the Official Charts Company shows that some artists – such as Royal Blood and Jungle – have seen massive sales since the Mercury shortlist was announced on 10 September. Royal Blood, for instance, have sold 59,060 copies of their debut over the past seven weeks; then again, they had already been named the UK’s No 1 album on 6 September. Kate Tempest and GoGo Penguin more than doubled their sales figures, and Nick Mulvey’s 7,735 post-Mercury receipts represent a 33% increase on what he had before.

But although every nominated act doubtless found some new fans, the figures are deceiving. The hip-hop group Young Fathers and the jazz outfit Polar Bear saw respective sales surges of 31% and 33%, but these amounted to a mere 561 and 569 albums sold. Anna Calvi’s One Breath sold 800 copies since garnering the Mercury nod – a boost of just 6% – while sales of East India Youth’s Stolen grew by 765 units, or 13%. In the UK, 700 albums sold will not transform a band’s prospects.

These numbers are not a condemnation of the Mercury so much as a reflection of a fractured music industry. Very few albums are sold nowadays, even by the most critically acclaimed artists. When the Mercury prize is awarded tonight, its £20,000 jackpot may be the biggest payday the winning act ever sees.