In my work with clients, I’ll find marketers who are not familiar with the definition of a campaign response. A response is anyone who has responded to a campaign or accepted a call-to-action.
Examples include, someone who fills out a form on your web site, someone who visited your booth at a trade show, someone who registered for a webinar that you hosted with a third party vendor, someone who clicked on an ad and completed the registration form to access the content. A response is not someone who was sent an email or who opened an email, or someone who attended a conference, but did not visit your booth.
Where this concept gets tricky to understand is when you start talking about leads. Responses and leads are different. I like to think of responses as a Marketing metric as it is the sum total of prospects who respond to a campaign. Responses can be associated with leads or contacts. A lead is an individual prospect that Marketing deems ready for sales follow-up. Leads can have multiple responses associated with them.
Salesforce.com offers a robust Campaigns module that enables you to track all of your campaigns and campaign responses. Learn more about how to use Salesforce campaigns in their campaign implementation guide.