For the first time this notion was used by Richard Sears and Powel Crosley Jr. They were mail order sales pioneers in the USA. They put this term into practice in order to win the confidence of consumers and to attract as many customers to their top quality service as possible.
If a customer isn't satisfied with a product or service he has a right to have his money back and the company guarantees this refund. Refund is usually made within 7 days (can be more) but it all depends on the company and it all is written in TOS. Before signing up for any hosting package plan a client has to read these terms very thoroughly to avoid any issues in future.
Nowadays nearly all web hosting companies do it to attract more clients to their company them to use only their service.
Hosting companies accept different methods of payment, such as Paypal, Fathard, E-Gold and credit cards. But as for the last they are often stolen and the owners of the hosting companies have great problems because of it. That's why the companies have to protect themselves and when a client pays with a credit card they contact him personally to assure him to do it but not the other person because if a credit card was stolen a company has to refund and pay extra money as a penalty for that they accepted stolen credit cards.
Chargeback is often done by the clients too. That is the process of taking back the merchant's credit card funds after the funds have been paid to the merchant. It occurs when a customer disputes a credit card transaction. The merchant must respond to the charge back and provide a proof that the product or service was provided to the client.
Payment systems like Paypal, 2checkout, etc. do a chargeback even if it's not host's fault. They are always on the merchants? side.
One more an essential thing that must be mentioned a web hosting client must provide true data about himself if he wants to avoid the possible problems in future.
Please Note!
Before you choose a web hosting company, read its AUP very thoroughly if you want to avoid hidden agenda that may occur.