The telephone answering services in call center business

Call center services are a valuable tool to any business, whether it is small or large, but just one of the many services that they offer is telephone answering services. This service is used on a wide scale for many different sorts of businesses, and usually comes as a part of an overall package. 
These services are useful for any big or small business who wants to operate twenty-fours a day and seven days a week. The beauty of having an answering service is that a trained and trusted operative can basically fill in for your usual staff outside of business hours. This may be useful for any business who deals with foreign customers where time zone differences could make communicating via telephone difficult.
What does this service provide me with:
This service can provide you with the ability to communicate with customers twenty-four hours a day and seven days a week. Using a professional agent, they will answer the phone and note down any queries that a customer may have for you. These agents are completely at your disposal and are usually willing to work on holidays, weekends, and in the middle of the night if you regularly deal with foreign customers.
Additional call center services, which can be included with your typical answering service, is the ability to have the agent immediately call you directly or to call a designated member of staff. Your operation can be as big or as small as you desire so you could essentially have a rotating schedule where one member of staff is "on call" at a specific time from home.
This can save on costs as you don't have to constantly open up your physical place of work during holidays or weekends because you have the answering service to act in your stead.
Again, you could simply just use voice mail or other recording services but the sad truth is that new customers want their query answered now and not later. As a result, there is a strong chance that a potential new customer will just give up and go to another company who does utilize answering services.
A final point
All of the above information is based on a company which offers these telephone answering services to their customers. It's also based on the assumption that you are working with a reputable and professional company, rather than a sub-par one, so please take this into account when deciding if you are going to purchase these services.