The product is called, loosely, Dragon Dictation. It’s made by a company called Nuance. There are versions for the PC, an old one for the Mac, and a mobile version that works a little differently.
If you have a podcast, you have some, well, power, authority, credibility. Just like if you have a book, you instantly have some leverage...
In a nutshell, the answer to Why Now? is because we can. Sure, microphones and book narrators have been around a long time. But...
Audio has been around since, I suppose, the spoken language. The difference now is distribution and availability. Audiobooks, podcasts, smart phones, voice controlled home...