I don’t think the client was stupid or the system was too complex, actually. The UI was good.
I think the issue was that the client didn’t exactly understand or trust what was going on. They had no reason to believe that the system worked or they wouldn’t lose or confuse people, since it was a totally new, totally digital version of what they’d previously always done.
It was slightly more complex than just buying pdfs, because the pdfs were generated on the fly with encryption and password protection, and the content was the heart of the client’s entire business. So, they were worried that people would be able to somehow steal or share the content with the new system.
I fully believe the problem was that we didn’t teach them or instill any confidence in the tool, though, and I don’t blame them at all for not trusting it. It’s a shame, but now we’ll never let that happen again.