Telemarketing is different from teleprospecting, which is also called inside sales. While they are both widely used marketing techniques, they are each appropriate for different needs.
Telemarketing is often referred to as cold calling. Telemarketing agents usually make unsolicited calls to a prepared list of numbers and closely follow a script. The goal of these calls is to make a sale.
Teleprospecting, inside sales or lead generation are activities that are more carefully targeted. Their goal is to identify the clients that are most interested or would most benefit from the product being sold so that the company knows where to direct its sales efforts.