Steam users must now disclose when they're being paid to promote a product on the service.

A new clause added to the Steam Subscriber Agreement requires all Steam users to declare whether they've received monetary exchanges, a free game key or any physical goods when writing reviews, compiling a Curator’s List, or streaming a game over Steam Broadcast.

“If you use Steam services (e.g. the Steam Curators’ Lists or the Steam Broadcasting service) to promote or endorse a product, service or event in return for any kind of consideration from a third party (including non-monetary rewards such as free games), you must clearly indicate the source of such consideration to your audience.”

In October 2014, Steam required all Curators to declare sponsored content and paid endorsements. This new amendment covers all aspects of the service.