I recently started listening to a podcast from the 30-yr-old Sears Radio Theater, which was an ambitious but short-lived attempt to recapture the golden days of radio. Sponsored by Sears, the five-day-a-week series featured big stars hosting big stories of adventure, love, etc.
Here's a link to the episode I wanted to hear, titled "Then There Were None." However, as you'll discover if you click to listen, the episode is larded with two kinds of commercials.
First come the Old Time Radio Network ads for Brookstone, etc. When those are finally over, the original radio intro starts. Sears wanted to get its money's worth and as the sole sponsor, it sprinkled ads throughout. Not just one or two ads at the start, but lots of ads at regular intervals. Sadly, I never finished the podcast because of all the commercial interruptions. Life is just too short and there are too many other podcasts waiting to be explored.
Podcasters, please keep your ads short and to the point. NPR's podcasts are a good example because they weave in the name of the sponsor without hitting listeners over the head again and again. Why risk annoying listeners? A gentle reminder goes much further than heavy-handed hard sell.