Great letter Clavus! TV screens in the grocery store are the evil. We had forty (40) such screens in the store I work in, showing regular commercials and "cooking shows" in what they told us was 20-minute batches but what felt like five minutes. It got really old really fast. At first they had the volume on fairly low, but increased it after a while because customers didn't notice them enough. The staff? We'd sing along in the more obnoxious commercials. Some of us planned to post an offer of "Buy 3 plasma screens for only $4999" on April 1st, but since our customers have no sense of humor whatsoever we didn't dare.
The only thing that has gotten better since the store was bought by a competitor chain is that the TVs are gone. Corporate handled the buyup so bad that as an added bonus there are also less customers in the store nowadays, so it's almost too quiet.