I built this in 2016 and, in fact, it has made some money ... a handful of people have, indeed, purchased custom Oh By Codes. But very few.
I remain convinced that there is a collection of interesting, compelling use-cases for Oh By Codes but I, and others, have not come up with them yet ...
[1] https://0x.co
It's pretty much common knowledge now that if you see a QR code, you scan it with a phone app, and it takes you to a webpage or something. It's maybe a little inconvenient to have to scan it with a phone at visible range, but you don't have to remember a bunch of funny codes, and if you get one wrong, it breaks entirely with no indication of where the mistake is.
Meanwhile, nobody knows that if they see 0xABCDEF, that means they should go to the URL https://0x.co/ABCDEF with the closest web browser.
It might be handier if it could generate a printable webpage or PDF or something that had the QR code for the URL and also the full URL with the short code. Now you have a solution for easily putting messages in QR codes that also has a fallback for users who don't have a phone, don't have a phone app, don't want to mess with their phone that minute, etc.
The platform/idea really doesn't work unless masses of people are trained, as you suggest, to recognize 0xABCDEF as discoverable on 0x.co.
We'll see ...