In contrast, content sites commonly charge a fixed price per click rather than use a bidding system. PPC display advertisements, also known as banner ads, are shown on web sites with related content that have agreed to show ads and are typically not pay-per-click advertising.
A service-level agreement (SLA) is a contract between a service provider and its internal or external customers that documents what services the provider will furnish.
Service plan. A service plan is a contract to purchasers of products for an additional fee. While service plans resemble extended warranties, there are several important differences between the two, often cited by retailers that sell them.