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.
While not disposing of the need for a project-specific contract, a Master Service Agreement can define the general terms of the business relationship, such as payment terms, intellectual property ownership, confidentiality, governing law and procedure for dispute resolution.