I know that the answer to the question "The pop idols are described as what other thing?" is in "The success of American Idol has been described as "unparalleled in broadcasting history". The series was also said by a rival TV executive to be "the most impactful show in the history of television". It has become a recognized springboard for launching the career of many artists as bona fide stars. According to Billboard magazine, in its first ten years, "Idol has spawned 345 Billboard chart-toppers and a platoon of pop idols, including Kelly Clarkson, Carrie Underwood, Chris Daughtry, Fantasia, Ruben Studdard, Jennifer Hudson, Clay Aiken, Adam Lambert and Jordin Sparks while remaining a TV ratings juggernaut."". Can you tell me what it is?
A:
Billboard chart-toppers