I've been watching this thread for a while, wondering if I should jump in. Well, here I am.
I'm a music teacher who picked up and teaches ukulele, and I fell in love with it. I love what it did in my life (restored my love of music--I was teaching middle school choir when I found ukulele and brought it to my students) and what it does for others as I attend ukulele events.
I "give back" by making resources for others...generally for beginners...and only have one item behind a paywall (A $9 item), and then everything in that item is actually available free (from me) elsewhere. I have started making some money from YouTube (a whole $30 a month at this point) and some ukuleles are sent to me free to review and keep. That's all wonderful, but I can't quit my job and I really don't want to. And I don't have the time to be a virtuoso as a player...I just grow as I play and learn, sometimes from others. It's a hobby for me, even if I'm put in 30 to 40 hours a week at it at times (this new beginner series was a massive effort this summer).
So I respect the heck out of Terry and what he has done. I don't know what his life was like before this (I should see if he has made a video about this), but at some point he clearly fell in love with the ukulele, and decided he wanted to make his life about it.
If you want to do ukulele full time (I think Brad, the original poster, does), you have four options. You can be a performer, you can be a teacher, you can do social media, or you can do sales. It's hard enough to make it in any one of the four, and people often do a combination.
Example? AnueNue with Corey and Kalei. Performers, teachers, and now sales.
And social media suddenly became much more complicated, as all the performers went online. Thankfully, sales of ukluleles went through the roof!
Back to Terry...He teaches--and I'm not going to rate the teaching or style--but he also hits rare areas, niches, of baritone and guitarlele. He has an online presence on YouTube and Instagram. And he has the store. He has consistent branding, a consistent presence, and his social media efforts usually cater to the entry level players--which is where the money is. His market is NOT ukulele underground.
He also seems to be on good terms with the KoAloha people, but it also seems like everyone is on good terms with the KoAloha people, because they seem to be good people.
I try to avoid superlatives. For a few weeks this summer, my ukulele play alongs channel had the most subscribers of all of them. I was proud of that, and didn't say anything at the time, which was good, because my friend Rachel Webley's channel blew by mine a few weeks later. Ultimately, that channel has over 61,000 subscribers (and generates $0) and is on its way to 100,000 (the goal), and that's all I can hope for.
I'm not a fan of Terry saying, "The number one store" or "The number one ukulele community" or so on. But it doesn't sound that good to say, "We're a really good store, too," or, "Well, if you can't find it at Mim's/The Ukulele Site." I wish we didn't have to try to sell ourselves like that, but marketing is marketing.
Which again, is why my job remains as a music teacher (I'm now teaching elementary, by the way, and ukulele to 5th grade).