A measure of how well a Web page meets federally mandated criteria to eliminate barriers in access to and delivery of electronic information, such as Web sites.

A subset or filter of your list or visitors. For example, all New Yorkers could be a segment of your full list.

The person or organization responsible for transmitting the email, usually identified by the email address in the ‘From’ line.

The protocol used on the Internet to transmit email.

A visit in which only one page was viewed and entry and exit pages are the same. (Also: Bounce)

A soft bounce is the failed delivery of an email due to a non-permanent reason, such as a full mailbox or unavailable server. A soft bounce indicates that the sender should try resending the email.

Also refered to as hosted software, where the software vendor hosts the application on its own servers and customers access it via a Web interface.

Unsolicited commercial email (UCE) is commonly referred to as spam, from the Monty Python skit where a restaurant serves nothing but spam.

The receipt of a complaint from an email recipient who has identified the message as spam. (Also see Feedback Loop)

The title of the email communication. This is the first (and hopefully not last) element of the communication recipients will see when they access their email. It has to grab attention and be credible or the email will not get opened.

Selecting a portion of a mailing list or site traffic based on similar characteristics or behavior and presenting Web content or sending messages created to capitalize on that targeted characteristic or behavior.

The most general part of a domain name, such as .com or .fr.

Collecting and evaluating the statistics from which one can measure the effectiveness of an online marketing campaign, including email, banner ads, and paid search.

Scripts that automatically track and report data relating to Web site visits and interactions.

The number of visitors to a specific Web page.

An email message that is primarily intended to facilitate, complete or confirm a commercial transaction that the recipient has previously agreed to enter in with the email sender. Also known as "relationship email message".

(Source: Commerce Committee Report, CAN-SPAM Act of 2003)

The basic protocol used to transmit information on the Internet.

A unique click is a single click by a single user. When unique clicks are measured, it is an aggregate number of how many times that URL was clicked by individual users (not the complete total of all users, all clicks.)

The number of individual people who visit a Web page within a set time. Unique visitors are counted only once during a session, no matter how many pages they viewed or how often they return to a previously viewed page.

Commercial email sent without the recipient's express permission. (also referred to as Spam)

The action a person takes when he or she chooses not to receive email communications. It requires a Web-based mechanism by which people can ask to be removed reliably from an email list. This request must be honored within ten days. (Also see Opt Out)

Shorthand for Universal Resource Locator, the Internet address for a Web page. It includes the protocol, the domain and the name of the file.

The number assigned to a Web page after it has been edited, to indicate it is different from the previous version. Each time content is changed and checked back into a content management system, a copy of the content is saved and its identifier (version number) is incremented to indicate its difference from the previous copy.

An individual interaction with a Web site, such as a page view. The visit begins with the first page view and concludes after a length of time when no action is reported.

The total length of time on the Web site during a single session.