It's a real shame they don't talk more specifically about Luhn's role in the 'record addressing' problem.

Back in 1953, IBM was investigating disk storage for record retrieval in large volumes of data. Seek/read time on these machines was on the order of a second, so a 10 level binary search could take around 10 seconds of total time. Unfortunately for IBM, this wasn't an improvement over the best human-driven manual lookup processes... which is an issue if you're trying to sell/lease expensive computer hardware.

With this as motivation, Luhn then essentially invented what we now would know as a hash table, which was key to the 1956 RAMAC release.