I'm wondering whether people who complain more have more problems in life. For example, the few people I know who really like to complain to customer service folk always seem to be on the phone, griping about whatever travesty is currently first on the list. I'm all for getting a better deal, but I will not complain for the sake of complaining. Chronic complainers have a shining aura of entitlement surrounding them. And sure -- to shut them up, an extra perk or two may be granted by the supervising authority on the other end of the conversation (e.g. more minutes, a free month, a partial refund), but in return, a large part of their life is devoted to negativity and bitching.
And now, an exercise in hypocrisy: It's annoying! Do it in private, please!