The joy of spelunking

Like any self-respecting nerd, I have spent many years listening to 99% Invisible, the podcast about the hidden design that surrounds us all. It’s really the podcast success story that everyone should learn from: a small radio spot that was extended by host Roman Mars from his bedroom and then turned into a genuine, consistent and creative media outlet. And it’s even survived acquisition relatively unscathed, which is rare: five years ago, when 99pi was bought by Sirius XM, the fear of what would come next was deep—but aside from more advertising, I think the output has remained very much on track with where it was before. One recent instalment was called 1-800-PODCAST, a potted history of the toll-free telephone number. It, like all the show’s episodes, taught me about some things I hadn’t really thought much about before—why toll-free numbers first appeared, and how they really work. But my eyes were also drawn to the title of the episode. It was a joke, of course, but it was also…