Pros
Excellent pay if you are willing to put up with what you have to do for it. It's a good student or casual job while you are studying and if you don't need to work too much, you can feel your life is sufficiently balanced. They give you plenty of hours (hence plenty of opportunities for pay), you're usually expected to give 20 hours a week availability. For me it was a great location. It seems to me that most employees, phone operators and supervisors included, think the job sucks so in this way there is a good sense of solidarity and community because we all roll our eyes at each other and have a good laugh at the shocking things we sometimes hear from respondents. There are sometimes no numbers to dial so you frequently get to chat and have fun in the office. It's a very casual culture and you can wear tracksuit pants if you really want. If you show yourself to have a moderately good attitude to working effectively, you'll be appreciated by some of the more respectable supervisors. As for the employee base there is a great deal of diversity and you have the chance to meet people from all walks of life.
Cons
It's kind of a humiliating and depressing job. The nature of what I was doing as a telephone interviewer was calling respondents and annoying them in their households for surveys. You get nothing but abuse and hang-ups on minute by minute basis. It's also terribly boring and uninspiring work. The actual surveys are usually badly worded and so even if there are grammatical errors in the questions you have to read them robot-like and verbatim so that you sound like an idiot to the respondent. There are systemic limits to how friendly or human you can present yourself. Also sometimes you will be expected to outright lie to people about survey time commitments. Please keep in mind this is a casual, pay by the hour job. It is mostly young people but some older ones. The young ones and the old ones don't really mix much. Likewise there is a strong wall between the asian and non-asian workers (of which proportions are about 50-50), like they don't really integrate and make friends across the two groups much. The culture is probably, in general pretty disrespectful. For example the operators don't give a rat's ass about cleaning up after themselves in the kitchen. The supervisors (at least some of them) don't reward you for your good work and don't really care about you.