I've never used a Steam Controller, and I'd be willing to bet that most of you haven't either. It was announced in 2013 with a promise of "supporting all games in the Steam catalog," and after a less-than-impressive hands-on debut and some extensive reworking, we declared it to be "almost as good as a mouse" under the ideal conditions.
Valve has continued to work on it, and now it looks as though it's gearing up to give it a more concerted marketing push, too. "We're looking into making a highlight video of the Steam Controller in action/shooter games to be included in the Store page. If you would like your video to be considered please post a link here. Preference will go to videos that utilize trackpad + gyro configs," Valve wrote in the Steam Controller forum.
"We're hoping at least a few videos submitted would include a camera shot of the controller in the players hand. That's definitely not required, though please be sure any videos are of actual Steam Controller gameplay."
Naturally, the follow-up conversation includes arguments over what constitutes an "action" game, whether or not Overwatch is acceptable, and links to videos that belong to other people. What it doesn't have in abundance are videos of the sort that Valve is actually asking for—user-generated, with trackpad and gyro configs, and shots of the device in hand—so if you own one and want to make it (and your hands) famous, get out your camera and share a link to your masterwork in the thread linked above.