As outlined in the section on installing apps from AppExchange marketplace, you should properly evaluate the functionality and results of deploying an app within your Salesforce CRM organization. This concept is part of a wider concern, which addresses the way changes are applied to the Salesforce CRM application.
With the use of Salesforce sandboxes, you can properly evaluate and perform due diligence for new Salesforce functionality before deciding to roll it out to your users in the production system. In the case of an AppExchange app, if the app proves to be unsuccessful, then it need not be uninstalled.
Let's take a look at Salesforce Sandboxes in the next section.