Twitch was bought by Amazon three years ago and has largely been a separate entity, aside from the Amazon Prime benefits for Twitch. Today, Twitch has announced "Gear on Amazon," which allows streamers to list the "gear" they use like monitors or graphics cards to their audience to purchase from Amazon.
If you stream on Twitch, your viewers have probably asked you about your PC build, your preferred hardware, and your favorite snacks.Gear on Amazon isn't limited to strictly "gear" either, as seen in the quote above. Streamers will have the ability to display their favorite snacks to viewers as well.
While Gear on Amazon seems to be directly related to "gear" like PC parts and accessories, the Amazon Associates Program includes commissions on pretty much everything, including toys, too,s and apparel. You can find the whole table here for what Associates will receive for various categories. For example, streamers would earn 1% commission on video games and video game consoles.
With the whole system in place for other items, it would not be surprising to me to see streamers take advantage of trying to talk about other products. And considering that Twitch is branching out from doing just video games, having a system in place for pretty much anything Amazon sells would make sense. And Twitch acknowledges that the announcement may be focused on gaming streams, but millions of products on Amazon are available to use with Gear on Amazon, so musical streams, talkshows, etc can put up products.