YouTube appears to be taking on Twitch in a subtler way: by giving away subscriptions you'd otherwise have to pay for. Some Premium members have received prompts to choose a free channel membership (worth up to $5) each month, much like the free Twitch channel subscriptions that Amazon Prime users get. The perk is inconsistently available and doesn't appear to work for at least some of those who see it, but it's clear that YouTube has at least been thinking about a bonus like this.
We've asked YouTube for comment.
This could just be a test. If it represents a planned launch, though, it won't be surprising. With more top Twitch streamers heading to YouTube, there will be more people wanting to back their favorite broadcasters. This would give fans a way to offer support at no extra charge if they already subscribe to Premium -- and, of course, help YouTube boost Premium subscriptions in the process.
Update 1/27 11AM ET: YouTube tells Engadget this was an internal test that inadvertently rolled out to external users. It's not guaranteed an official launch, then, but it still wouldn't be a shocking move.