You're showering. You sing a particularly well-done version of "Baby's Got Back", or finish a stirring monologue on why exactly cows are black with white spots, and not the other way around. You wish someone was listening.
Now they are.
Soap Radio turns a normal bar of soap into a sort of CB radio.
You hold the soap up to your face (like it was a microphone) and start acting like you're on the radio. Other people hear you on theirs (if they aren't in the middle of their own shower meditations.)
Not everything you say will be gold, but that's alright. The bar itself is really just a dumb terminal, connected via wifi to a program on your computer. That program is quite good at voice analysis, and so can break up your stream of noise into distinct "segments". You indicate by saying "print that", or something similar, that you want to publish your last exhortation to the Soap Radio servers. Otherwise, the segments are silently thrown out (it's no good to be able to publish after getting out of the shower; otherwise we'd have professional DJs stealing away all our amateur-hour schtick! For this reason, the servers also require the sound of shower spray to be evident in the background for a submission to be valid, which they then strip out themselves.)
When you aren't pontificating, you're served a constant stream off of the Soap Radio servers. The servers have further analyzed your voice data to recognize whether your sermon is on a contemporary, topical subject (such as a recent electoral candidate) or one of more lasting interest (such as a one-man re-enactment of the Rocky Horror Picture Show.) "News" gets put in one queue (which expires quickly, so people don't hear outdated conversations, and is Last-In-First-Out), while everything else ends up in a big pool that is pulled from randomly, and never expires. They also recognize an ephemeral category for song performances by cross-referencing the Voice-Recognized lyrics to those of the songs on the top-40 charts.
Everyone can be served new and different tidbits, but I imagine most people will want to hear the same main feed, simply to get the same sense of community that people feel from being able to talk about the same celebrities. This main feed will be able to be served multicast to everyone's soap, greatly reducing the load on the Soap Radio servers, and increasing the bakability of the idea.
The business model could be by subscription to the internet service itself, or, more deviously, could come in the place of the radios. While the service is free, you have to buy the company's own brand of soap--big, bulky bars with a radio transmitter in a plastic shell in the center. These bars, like razor blades or gasoline, won't be cheap, as almost no one will consider returning the radio transmitters to the company for reuse when the soap is used up, instead electing to just chuck them in their bathroom refuse bins.
Finally, note that many of the Soap Radio segments will be reminiscent of the older radio dramas. Just think: Soap Operas with real Soap!