The Association for Downloadable Media announced an industry-wide proposal for advertising standards in podcasting and video podcasts. The highlights, as reported in Podcasting News:

• Insertions – Pre-recorded file provided by sponsor
• Time :10, :15, :30, :1:00
• Location: pre roll, mid roll, post roll
• Frequency: variable by episode or time period
• Audio: 128k stereo/64k mono mp3
• Video: H.264 mp4 Aspect: 4×3 or 16×9 – sd and hd
• Content Participation – sponsors message included in show
• Time: variable from :1 second to full episode
• Location: pre roll mid roll post roll or integrated w/in episode(s)
• Frequency: variable by episode or time period

Check out the ADM website for more. I like the concept of standards here, but as I’ve been posting lately, podcasters that are in it to make some dineros should probably seek to diversify beyond just ad revenues.