ad space - the space on a Web page available for advertisements.

affiliate - the publisher/salesperson in an affiliate marketing relationship.

affiliate marketing - income sharing between online advertisers/merchants and online publishers/salespeople. 
Payment is based on performance measures, typically in the form of sales, clicks, registrations, or a hybrid model.

affiliate merchant - the advertiser in an affiliate marketing relationship.

affiliate network - intermediary providing services for affiliate merchants and affiliates.

affiliate software - software that provides tracking and reporting of sales, registrations, or clicks from affiliate links.

bookmark- a link stored in a Web browser for future reference.

banner ad - a graphical web advertising unit, typically measuring 468 pixels wide and 60 pixels tall (i.e. 468x60).

button ad - a graphical advertising unit, smaller than a banner ad.

click-through - the process of clicking through an online advertisement to the advertiser's destination.

click-through rate (CTR) - The average number of clicks-through as a percentage.

conversion rate - the percentage of visitors who take a desired action.

cost-per-click (CPC) - the cost paid by the advertiser to Google etc per click-through.

CPM - cost per thousand impressions.

customer acquisition cost - the cost of acquiring each new customer.

deep linking - linking to a web page other than a site's home page.

description tag - an HTML tag used by Web page authors to provide a description for search engine listings.

doorway/portal domain - a domain used specifically to rank well in search engines for particular keywords, serving as an entry point through which visitors pass to the main domain.

doorway/portal page - a page made specifically to rank well in search engines for particular keywords, serving as an entry point through which visitors pass to the main content.

ezine - an electronic magazine, whether delivered via a Web site or an email newsletter.

ezine directory - directory of electronic magazines, typically of the email variety.

Hit - request of a file from a Web server.

home page - the main page of a Web site.

HTML banner - a banner ad using HTML elements, often including interactive forms, instead of (or in addition to) standard graphical elements.

inbound link - a link from a site outside your site.

JavaScript - a scripting language developed by Netscape and used to create interactive Web sites.

keyword/keyphrase marketing - putting your message in front of people who are searching using particular keywords and keyphrases.

keyword - a word used in a performing a search.

keyword density - keywords as a percentage of total text on a web pages etc.

keyword research - the search for keywords related to your Web site, and the analysis of which ones yield the highest return on investment (ROI).

link text - the text contained in a hyperlink.

link checker - tool used to check for broken hyperlinks.

manual submission - adding a URL to the search engines individually and in person.

meta tags - tags to describe various aspects of a Web page.

opt-in email - email requested by the recipient.

outbound link - a link to a site outside your site.

pay per click (PPC) - online advertising payment where the host of the advert is paid by the numbers of clicks-through.

pop-up ad - an ad that displays in a new browser window on top of the viewing page.

pop-under ad - an ad that displays in a new browser window behind the current browser window.

reciprocal links - links between two sites, based on an agreement by the site owners to exchange links.

site stickiness - the amount of time spent at a site by a average visitor.

shopping cart - software used for online ordering, whereby visitors may select, view, add/delete, and purchase merchandise.

search engine - a program, such as Google, that indexes documents, then attempts to match documents relevant to the users’ search requests.

search engine optimization – the process of designing a site or page so that it rates highly with search engines

search engine submission - the act of supplying a URL to a search engine in an attempt to make a search engine aware of a site or page.

title tag - HTML tag used to define the text in the top line of a Web browser, also used by many search engines as the title of search listings.

text ad - advertisement using text-based hyperlinks.

unique visitors – number of individuals who have visited a Web site in a given time, typically a 30 day period, rather than the total number of times a site has been visited.

URL - location of a web page on the Internet.

viral marketing - marketing strategy that encourages people to pass along a marketing message.

Web site traffic - the amount of visitors and visits a Web site receives.

Web browser - a software application that allows for the browsing of the World Wide Web.

Web design - the selection and coordination of available components to create the layout and structure of a Web page.

Web site usability – how easy a site is to use..