Think of a store where you like to go shopping. Ask yourself why do you like this store more than another one. The answer might be because you know the store well and you trust it. This store probably has a great reputation, which contributes to your trustiness to this merchant. To know if a merchant has a good reputation, if the store has a great customer service, you can rely on word of mouth or on a firm of experts in this domain. This company, called Gomez, is specialized in on-line merchants certification. They provide a good idea about if merchants offer good services to its customers.