Hi Jim, Toby's channel has a lot of viewers that are not in the Cat collector community but rather are folks that just like the style of video (working on old equipment, being thorough and fully descriptive which Toby does very effectively), and his content is arranged as a set of multi-episode stories, engaging the viewer and making him want to come back for more. Plus, the bonus for these tractor stories is that at the end, the machine "comes alive" and that's the ultimate reward for following the story. This is typical of many popular youtube channels where the content provides entertainment, just like the movies. I watch youtube on content that I'll never be a part of, but find interesting. Movie makers do the same thing with their prequels and sequels - my kids can't wait for the next Marvel superhero movie : )
I think that's the challenge for any club, which is how to turn "idle" interest into actual memberships involving an outlay. Unfortunately there seems to be no secret sauce, although it is true that the candidate has to see a tangible value to make him take action