Lucas Shaw, writing at Billboard:
In recent months, YouTube has given a handful of musicians a couple hundred thousand dollars to produce videos and promote their work on billboards, part of a larger campaign to improve the site’s relationship with the music industry.
Yet such support comes with a catch, with some musicians required to promise the won’t say negative things about YouTube, said the people, who asked not to be identified discussing private business transactions. Non-disparagement agreements are common in business, but YouTube’s biggest direct competitors in music don’t require them, the people said.