Each episode will feature at least one advertisement. You can place several if you want. If your podcast does not exceed 20 minutes you MUST have at least one advertisement. If your podcast is 20 to 40 minutes, you must have at least two advertisements. You are allowed to have a MAX of 1 commercial per every 5 minutes of recording time. This rule was introduced to prevent users from creating podcasts and inserting 100 advertisements in the podcast and getting them auto downloaded.