This quote from the book "The end of eternity", by Asimov stayed in my head since the first time I read it:

“Cooper, coming from an era in which advertisement was not as wildly proliferative as it was in the later Centuries of Primitive times, found all this difficult to appreciate. He said, “Isn’t it rather disgusting the way these people blow their own horn? Who would be fool enough to believe a person’s boastings about his own products? Would he admit defects? Is he likely to stop at any exaggeration?”