This telemarketing is to call people all day to promote domain names, websites and so on. For example, our department has to answer more than a dozen such calls a day, which is really annoying. When doing telemarketing, 80% of the calls will be directly told not to hang up, or directly scold you not to call again. A good-natured person may talk to you after receiving it.
Moreover, telemarketers basically have rules on how many calls to make and how long to make every day. For example, the telemarketer of the company I used to work for had to make 80 calls every day, and the call duration should reach 120 minutes, otherwise the money would be deducted.
Of course, if you want to challenge yourself, try it. It's very exercise. However, it is not bad that there are a few successful people in 100. It's too much pressure to do this, so it's better to do other business. Not by phone, but face to face.