what are campaigns in salesforce?

Campaigns in Salesforce are outbound marketing projects (e.g., direct mail program, seminar, print advertisement, email) that you want to plan, manage, and track within salesforce.com. Both leads and contacts can be added to campaigns. You can organize campaigns into hierarchies for easy analysis of related marketing tactics. All campaigns are executed outside of salesforce.com but you can track their response and analyze their influence on new business. Opportunities can be configured to either manually or automatically associate multiple influential campaigns to determine what marketing efforts impacted sales.