Podcasting is just one of the many channels that companies have available for distributing content, and is the primany way of delivering audio (and increasingly video) to time-shifted listeners. Whilst a lot of podcasts are 'homegrown' operations done with a mic and some free software, quite a few companies are using this medium to get their message across.
This has been particularly adopted by media companies that already produce high-quality content. Obvious examples are:
The Guardian Newpaper:
There have been stories recently that raise the question of whether Podcasting is failing? However, these reports are a little premature and do not really understand how the 'Long Tail' can be leveraged successfully by podcasting. The "Power to the People: Social Media Tracker" study in April 2008 estimated that just over 14% of US Internet users downloaded podcasts in 2007. eMarketer also predicts in a recent article that US podcast ad spending will grow to $435 million by 2012 from $165 million in 2007
It should also be noted that Podcasting has additonal benefits such as Search Engine Optimisation, if done correctly: