On Monday, Twitch announced a major downgrade coming soon to its paid Twitch Prime service. Starting September 14, any renewal of the paid service (as part of a paid Amazon Prime subscription) will have its no-advertising benefit lopped off.

On that day, existing paid Amazon Prime (and thus Twitch Prime) subscribers will continue receiving an ad-free viewing experience on the site, which revolves primarily around video game live-streaming. Any renewals paid for after that date, either on a monthly or annual basis, will flip the switch and turn video ads back on, to be played at random intervals during Twitch video streams.

In short: if you want to reap ad-free Twitch benefits via Amazon Prime for as long as possible and you like paying for Amazon's service, re-up that subscription ahead of September 14.

After that offer expires, Twitch is still happy to get its members back to a no-advertising experience... at an additional cost. By paying $9 per month, Twitch members can add a "Turbo" membership to their profile, which disables ads across the entire site and adds a few other perks (cosmetic options while chatting in Twitch, larger video storage for video creators). Should viewers simply want to skip a single channel's ads, they can pay that channel's monthly subscription cost, though this varies on a channel-by-channel basis. (Twitch hasn't made it clear whether those channel hosts lose revenue by offering a no-ads option to their subscribers.)

"Advertising is an important source of support for the creators who make Twitch possible," Twitch wrote in its announcement to subscribers. "This change will strengthen and expand that advertising opportunity for creators so they can get more support from their viewers for doing what they love."

The other update in today's announcement is more Amazon-centric: a change to its pre-order discount on new video games. Instead of offering a 20-percent discount on game pre-orders, Amazon will now offer its paying Prime members a $10 credit towards future orders. In some cases, that's only a slight change in total discount (with $60 games being discounted $10 instead of $12), but pricier special editions will see their discounts drop more significantly—and either way, this forces an additional purchase to redeem the "discount" on offer.

Twitch Prime still comes with significant perks as part of the $119/year Amazon Prime subscription cost. That includes a single paid subscription per month and a bevy of free PC game downloads (through Twitch's desktop client) that do not expire once a Twitch Prime membership ends. Still, the ad-free option, spread across the entire site, is a pretty significant perk to lose for avid viewers, and the fact that Twitch wants $108/year for the perk seems to indicate how much value it assigns to the site's advertising potential.

The news follows an advertising-related announcement by Netflix last week: the leading video-subscription service has begun testing ads for its own series as interruptions between other series' binges.

This article has been updated to clarify changes to Amazon Prime's pre-order discounts on games.