It has a very good reputation.
From the very first moment you meet the senior manager, you know that telemarketing is an extremely exploitative job: performance comes first, with nothing else coming second. They speak very bluntly, to the point of showing no mercy. That may be a good thing—it weeds out interviewees who cannot accept the company culture at the very first stage. Basically, it is a place to train your liver and your ability to withstand pressure.