Alicia Keys' "No One" is RCA's first-ever gold-selling ringback tone, with 500,000 downloads, according to the label.

Ringback tones are song clips that mobile users can choose to play when others call them. Unlike a ringtone, which the called party hears, only the calling party hears the ringback tone instead of the standard "ring ring" normally heard.

By way of comparison, "No One" sold more than 2 million master ringtone copies. In total, Keys has sold 4.3 million mobile downloads of one sort or another-including ringback tones, ringtones, full tracks and bundled offerings.