According to YouTube I joined up on 2006-09-04. I don't think that's quite correct. I did have a Google Video account from very early on, and uploaded a couple of things, and it got ported to a YouTube account when Google discontinued the original video service and settled on YouTube post-purchase. So I guess, in some respects, it's kind of correct.
For most of that time I had hardly anything on there. Couple of videos to do with the weather station I ran for a few years, some things related to my photography, couple of things related to hacking with code; that's about it.
Then, a couple or so years back, when I got heavily into PCVR gaming, I started to record my gaming sessions and upload them.
As of the time of writing there are 1,109 videos in the PCVR playlist, and around 1,300 videos on my channel in total.
As for subscribers... eh, come on, few people are really interested in watching some old bloke stumble around in VR, and I was very late to the game anyway. But, apparently, around 350 lovely folk care enough about my nonsense to subscribe.
Nowhere near enough for a YouTube play button, that's for sure. Only... I now have a play button!
I mean, sure, I have to build it myself...
...but it's something to show for all my efforts, I guess. ;-)
As for how I got it: presumably anyone/everyone with a YouTube account with some content got the offer of goodies (I also got offered free coffee, sausage rolls, socks, and a bunch of other stuff I've forgotten), and I was lucky to claim one of these almost the instant the email turned up.
It's very likely the only YouTube play button I'll ever receive. I think it will take pride of place on my desk.