The difference here is that orders placed by USPS mail were subject to mail fraud regulations _and enforcement_ --- that was _not_ in place for early internet ordering.
My kids were quite amazed when they found my copy of a book whose approximate title was _Specialty Mail Order Catalogs_, which is apparently so obscure I'm not finding it on Goodreads or Abebooks --- will have to check the ISBN the next time it comes up and add it to the former.
My father's stereo system was installed in our living room, a Heathkit with discrete components, probably a tube-transistor hybrid type. I did not witness him in the process of assembling it.
But in those days, there were the trade magazines on the newsstand, the electronics shops and clubs where guys hung out to talk about calculators and radios and jukeboxes and pinball machines.
It looks like MITS was already into calculators and model rocketry. And getting featured on the cover of Popular Electronics gave them a boost. Undoubtedly, plenty of ads in the back for mail-order kits, and then you'd be signed up for ever-more specialized company catalogs.
It was the same when I collected vinyl records and built computers. Find the right trade magazines and the crusty old guys tending storefronts, and you could learn about the next big thing.
Of course there were also comic books sold to gullible children with catalogs and ads in the back pages. Snapping gum, whoopee cushions, spy cameras, and X-ray Specs. You could count on being disappointed by purchasing something on that list, but it was often a matter of clever misrepresentation by marketing blurbs and a sketch.
One night 8-year-old me phoned in an order for a "remote control hovercraft". It came "collect-on-delivery" which Mom didn't like. The hovercraft was not radio-controlled as I had imagined. It had a flashlight-like handle that held 2x "D" cells and a motor that rotated a thin cable. The cable stretched several feet to a "hovercraft" with a light plastic hull and fan blades. So you could walk it around the room like a marionette as the downdraft held it suspended a little bit.
Only a few years later, I began receiving mail from AARP. The hovercraft sellers had sold them my address and pseudonym. We could tell, because the hovercraft-selling lady had misspelled my first name. Good times.
> The hovercraft was not radio-controlled as I had imagined. It had a flashlight-like handle that held 2x "D" cells and a motor that rotated a thin cable. The cable stretched several feet to a "hovercraft" with a light plastic hull and fan blades.
I had one of those, though I knew what I was getting (from Edmund Scientific Catalog).
Edmund at least held on to the non-professional side of its optics business through Anchor Optical Supply. But yeah, I miss paging through the original catalogs. I think I still have the "How to make a Telescope" book although I lost the mirror blank several moves ago.
My kids were quite amazed when they found my copy of a book whose approximate title was _Specialty Mail Order Catalogs_, which is apparently so obscure I'm not finding it on Goodreads or Abebooks --- will have to check the ISBN the next time it comes up and add it to the former.