If you can arrange a site visit to the telemarketing call centers you are considering, you can get a wealth of information that may be hard to gather otherwise. Being in the actual call center can give you a sense of how the telemarketing company treats their employees. Are staffers energetic and pleasant? Enthusiasm and friendliness in person carries over to phone calls. This will also be a good opportunity for you to look at sample scripts, meet some of the agents who may be working for you, and get a sense of the scale of the operation.

A site visit is also your chance to conduct in-person interviews with the agents. In addition to basics like how happy they are, their tenure at the company, and the projects they have worked on, questions such as "What is your next job going to be?" can help you get some insight into their commitment to telephone sales.

Another important test is listening to actual calls. Pay attention to how well the agents know the material they are selling, the overall image they project, and how well they can improvise when necessary. This the most direct way to evaluate a telemarketing call center, so plan several listening sessions to make sure you get the information you need.

As with any major business purchase, you should request references of both current and former clients. If possible, ask for references to clients in businesses similar to yours, both in industry and size. Some questions you may want to ask when contacting references:

• Did you accomplish your overall goals when working with this company?
• Were you able to get all the metrics you needed around activity and results?
• What were the agents' biggest strengths and weaknesses?

To instantly compare telemarketing service offerings, explore mini web sites of multiple telemarketing firms at once.