Setting up "carpet cleaning appointments" for Electrosux, er, Electrolux vacuum salesmen by cold-calling people out of the phone book.
The carpet cleaning was secondary - it was really just a means of getting a high-pressure salesperson inside the homes of the gullible in order to sell them vacuum cleaners, so I had a lot of leeway in bargaining down the price, throwing in extra rooms, etc., in order to set an appointment.
The "call center" was the utility room in the back of an office in a dumpy strip mall. The room itself was probably 3'x5' - just enough for two chairs and two small tables, each with a phone and a phone book. If nobody else had checked off a number, it was fair game. There were two phone books, so some lucky people got more than one call from me and my coworker, a former chemistry PhD student with a drug and alcohol problem and multiple DUIs. We each chain smoked in that tiny, unventilated room for an entire summer.
It paid remarkably well though, something like $10/hr, plus $20 per appointment set, which was pretty solid pay for that kind of drudgery by mid-90s standards. We could each average about an appointment an hour, and I have no idea how they managed to keep paying us both, because some of those appointments were never, ever, going to turn into a sale.
The most enjoyable part of the job was occasionally calling the people who would go ballistic on telemarketers and deliberately provoking them, or just making juvenile prank calls (sorry, Livshits family!).