Comment by nicoburns
I don't particularly like the podcast format either, but it's not inherently less efficient. You can potentially do other tasks while listening to one which would be difficult while reading. I personally find it difficult to concentrate on the content of the podcast when I do this (I don't take in information well from auditory sources), but others don't (and some actually find it hard to remember things they read).
Same for me. I only can listen to podcasts when I'm folding laundry, and my laundry folding needs are limited so it takes ages to get through a single episode.