It sounds easy, but often isn't. Maybe radio spots are a little different because they're cheaper and usually more low-quality than TV ads, but it doesn't real

It sounds easy, but often isn't. Maybe radio spots are a little different because they're cheaper and usually more low-quality than TV ads, but it doesn't really work for TV ads - they often have small variations, e.g. 10sec identical, 5sec different, 10sec identical (easy example). Also depending on your method of analyzing the audio it's sometimes broadcast with an unhearable fingerprint that distorts the waveform (let's say like MP3 versus WAV, but worse). So yes, you can find some patterns - but the commercial breaks are highly mixed up and you wouldn't believe how many distinct commercials per channel are there, even if you think you hear the same ones all the time :)