Not a streamer. Not an "influencer". Not friends/family with Blizzard staff. I'm nobody, really, and I got in. I can only think it was some combination of sheer luck plus the fact (maybe?) that I started playing on the first day of release - I pre-ordered the vanilla collectors edition - and have played pretty steadily since then - though I've had at least a couple of year-long breaks and certainly don't play as much now as I did back in the day.
I enjoy betas; I enjoy testing and giving feedback - so I'll do my best to respect and appreciate the fact that I got in and will try to be useful. Good luck to anyone hoping for an invite!