Notify affiliates of the introduction of the SDA model, and any other changes to advertising practices, via e-mail prior to implementation.
I discovered the existence of SDA not as an Affiliate, but as a viewer. I was surprised to see one of my favorite streamers running an inline ad - only to find out they were TOTALLY UNAWARE of the ad being run on their stream! After some investigation I discovered the existence of the SDA program. I like the program and I see a lot of potential for Twitch and its streamers to benefit from the program, but it is highly invasive to do this type of advertising without notifying streamers independently and prior to launch. I'm glad to see Twitch branching out and exploring more options to benefit their platform and broadcasters, but the opacity of this deployment leaves much to be desired. I spent a long time looking into these "phantom ads" before discovering this program, and that was a lot of stress that could have been avoided by simply sending out a blanket e-mail.
Furthermore, Twitch did send a blanket e-mail on Sep 13 concerning the new Ads Manager, and there is no mention of the deployment or implementation of Stream Display Ads. A simple heads-up would have prevented this feedback!
PLEASE, BE MORE TRANSPARENT ABOUT CHANGES TO ADVERTISING AND NOTIFY YOUR BROADCASTERS BEFORE YOU DEPLOY THESE CHANGES. I like SDA's and I like having more options for streamers and viewers. I do not like surprise changes that alter my broadcast inline.