Bosses at the record company, including Pop Idol's Mr Nasty Simon Cowell, are apparently surprised at how well it's done.
And now they are worried it will ruin the chances of Gareth's new record - Anyone Of Us - reaching the top chart spot, says the Sun.
Because BMG have spent so much money on the young star, they want to make sure this effort does just as well as his debut single, Unchained Melody.
The single, Gareth's second, is due out on Monday but we'll have to wait another week to see if it makes number one.