It’s finally happened. Four months after the launch of T-Mobile’s Binge On video streaming option, the Un-carrier has finally wrangled its biggest catch: YouTube.

T-Mobile announced YouTube’s annexation on Thursday, alongside the addition of Baeble Music, Discovery GO, ESNE TV, FilmOn.TV, Fox Business, Google Play Movies, KlowdTV and Red Bull TV.

Binge On now has more than 50 video partners whose services represent 70 percent of all video watched by Un-carrier customers, T-Mobile said.

But what made YouTube jump on board now?

Google revealed Thursday it was initially hesitant to participate because of questions raised by the launch of the service, including how Binge On would treat services that were not included in the “free streaming” portion of the program and how users could exercise control over the program’s options.

The tech giant said it raised its concerns to T-Mobile, which has responded to feedback from Google and others by improving notice and choice for users as well as information and choice for video services.

Some of the improved options for video services cited by Google include the newly announced ability for video providers to choose how Binge On’s video optimization will apply to their content.

Rather than having T-Mobile optimize the video stream, providers can now opt to provide their own mobile-optimized video at native resolutions to Binge On customers. YouTube will be one of the first to capitalize on this feature, T-Mobile said.

Additionally, T-Mobile is making it easier for video providers to exclude their content from mobile optimization or free streaming. Now, all it will take is an email to the Un-carrier and the ability to meet certain technical criteria so T-Mobile can identify their video streams reliably.

“We think these changes, which T-Mobile is making for all users and video providers on a non-preferential basis, can help ensure that the program works well for all users and the entire video ecosystem,” YouTube Product Management Director Christian Kleinerman wrote in a post on Google’s Public Policy blog. “As a result, YouTube and Google Play Movies & TV are participating in Binge On…We hope our users enjoy this new option.”

Since the program’s launch, T-Mobile said Binge On customers have streamed more than 57 million GB of video.