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Panoply has developed software for podcasts that allows them to inject targeted ads into downloads, which makes podcast advertising closer to the nightmare that we see on the web.

However, that could offer another avenue for ad-blocking. If you download multiple podcasts from different IPs, you can isolate the ads by finding the parts of the audio that are different.

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That's a great idea if the injected ads are exactly the same length and always get put in the same place. If you have a 30 second ad in one download and 40s in another, 10 seconds of legitimate podcast audio gets interpreted as an advertisement.

It works even if they don't, you just need a more intense algorithm to do similarity matching across all offsets.

With maximally repeated sequences, you can https://ieeexplore.ieee.org/abstract/document/6012115

You "just" need to find all the common segments between different downloads; those are very likely to be the actual content, and not differing ads. Naturally this doesn't work very well if the pool of ads is low and you get repeats.

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