Verizon has mobile ringbacks and they were one on the first mobile operators to offer the technology. This service allows verizon users to purchase mobile ringbacks to allow the sounds callers hear when they are waiting for a call to be answered. Verizon customers can browse mobile ringbacks from an initial catalog of more than 2,200 songs in 13 different music genres from Warner Music Group and Sony BMG Music Entertainment. Mobile advertisers are also interested in mobile ringbacks due to the possibility of another marketing medium being created.