system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is happening when one commercial is interrupted by/for another?

When I am watching television and it goes to commercial, occasionally and not too infrequently, I will see what is clearly the first five or so seconds of a commercial, and then it will quickly fade out and be replaced with a commercial on a completely different subject. Why is it that these commercials are being interrupted? And why is it so often so rough rather than a smooth interruption/transition?
gpt
Those are national or at the least very large area commercials that get cut short. Companies who pay to have their commercials show over all of the regions that a particular cable company caters to sometimes get overwritten by "local" commercials. These spots cost less but won't show up everywhere, just a specific region. It sort of just plays over whatever commercial is on the national broadcast :)