The Boomtown Rats rocker unveiled the 30th anniversary version of Do They Know It's Christmas?, featuring One Direction, Ed Sheeran and Coldplay's Chris Martin, during the broadcast of British reality Tv show The X Factor on Sunday evening and he urged the public to buy the single.
Geldof was amazed by the amount raised in download pre-orders following its Tv debut, telling BBC Radio 4's Today programme, "It's gone manic. That's the digital age.
"We promoted the single on X Factor, Simon Cowell gave us five minutes of the show last night. Within four or five minutes of leaving the show we had a million quid (pounds). That's extraordinary... From what we're seeing now from iTunes it's gone bonkers. The pre-orders of the thing were ridiculous."
The single was released on iTunes on Monday (17Nov14) and Geldof told Sky News that the music service "went down" a couple of times due to high demand.