Their No. 1 hit has become the first song to reach the 6 million mark in digital downloads.
The milestone was announced Friday and confirmed by Nielsen SoundScan. For the group's leader, will.i.am, the moment is about much more than the song.
"We came out in '98 and our career, if you would look at it on chart, there's no dips in it," he said in a phone interview Thursday. "For our career to still be healthy and vibrant and doing things like 6 million downloads, it's pretty significant."
It's also significant, he said, in a time when illegal downloading is the norm.
"That means that they chose to support the group, support the art," he said. "God knows how many people listened to it online and didn't buy it, downloaded it for free and didn't think about it."
The upbeat song about good vibes was No. 1 for 14 weeks; will.i.am said the reason it was so successful was because it gave people hope in a downward time.
"It's a positive, feel-good song at the time where there's question marks and uncertainty. People want to be reminded that it's going to be all right," he said.
The song was one of the hits from the group's multiplatinum The E.N.D., which was released last year. Although it is still on the charts, will.i.am said a new album, "The Beginning," is almost finished and likely due at the end of the year.
"It symbolizes growth, new beginnings and starts, fresh new perspective," he said.