A day after performing at this year's Grammys on Sunday night (February 13), Mumford & Sons have seen a huge jump in digital sales making them No.1 in both the Amazon and iTunes digital album charts.

Although the full effect of the Grammys on retail won't be evident for another week, the digital sales growth indicates a huge sales surge.

Mumford & Sons' U.S. label, Glassnote Entertainment, reports the band's debut album 'Sigh No More' had sold 31,000 copies via iTunes alone through Sunday night.

The week leading up to the Grammys, the UK band sold 25,000 copies in all digital outlets and physical stores.

The single that the band performed at the Grammys, 'The Cave', leapt from No. 108 in the iTunes chart the week before the awards event to No. 8 yesterday afternoon (February 14).

Watch fan footage of Mumford & Sons performing 'The Cave' at the Grammys pre-show party below: