Valve has added a new clause to its Steam Subscriber Agreement in which users now need to disclose whether they are being paid to promote a product on the service.
This applies to reviews, the Curator’s List and when streaming a game using the new Steam Broadcast feature.
The promotion disclosure applies to monetary exchanges, a free game key or physical goods.
“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.”