Melody Tan over at Aussie Adventures notes yesterday that it took Sony 10 tears to sell 50 million Sony Walkmans.
It only took Apple 4.5 years to sell that many iPods.
Part of this discrepancy can certainly be attributed to the the fact that Sony was truly breaking new ground with the whole idea of mobile audio. Apple was just introducing a new method of a now accepted tehcnology.
However, it's hard to deny that if 50 million iPods are sold in under 5 years that means there's a lot of potential podcast listeners out there. Never mind all the audio players sold that aren't iPods.
Massive opportunity to get your message into people's ears. Absolutely massive.