CLICK THROUGH RATE (CTR) - The ratio of the number of times a user clicks on an online advertisement per number of viewers who view the Web site that has the advertisement on it. For exampe, if one out of 100 people who visit a specific Web site click on the advertisement and are taken to the advertiser'ssite, then the CTR of that advertisement is 1/100, or 1%.

COST PER CLICK (CPC) - An Internet marketing formula used to price online advertisements. Advertisers will pay Internet Publishers based on the number of clicks a specific ad gets.

COST PER THOUSAND (CPM) - CPM is used by Internet marketers to price as banners. SItes that sell advertising will guarantee an advertiser a certain number of impressions (number of times an ad banner is downloaded and presumably seen by visitors.), then set a rate based oon that guarantee times the CPM rate. A Web site that has a CPM rate of $25 and guarantees advertisers 600,000 impressions will charge $15,000 ($25 x 600) for those advertisers' ad banner.

HIT - Also called a page hit. The retrieval of any item, like a page or a graphic, from a Web server. For example, when a visitor calls up a Web page with four graphics, that's five hits, one for the page and four for the graphics. For this reason, hits often aren't a good indication of Web traffic. Our preference is to only use the word "hit" when discussing baseball, not online advertising. Compare with page view.

IMPRESSION - An advertisement's appearance on an accessed Web page. For example, if the page you're on shows three ads, that's three impressions. Advertisers use impressions to measure the number of views their ads receive, and publishers often sell ad space according to impressions. (It can be tough to know, though, whether an impression really means a visitor saw the ad, since they could be browsing without graphicsor might not have scrolled down for enough.) Impresisons are tracked in a log maintained by a site server and are often sold on a cost per thousand (CPM) basis

PAGE IMPRESSION - The exact number of times a specific Web site has been accessed or viewed by a user. A page impression acts as a counter for Web pages, informing site owners how many times their sites were visited. Page impressions are also referred to as hits.

PAGE VIEW - A Web page that has been viewed by one visitor. Page views are often used in online advertising, where advertisers use the number of page views a site receives to determine where and how to advertise.

UNIQUE VISITOR - When tracking the amount of traffic on a web site, it refers to a person who visits a web site once within a specified period of time. Software that tracks and counts Web site traffic can distinguish between visitors who only visit the site once and unique visitors who return to the site. Different from a site's hits or page views -- which are measured by the number files that are requested from a site -- unique visitors are measured accoring to their unique IP adresses, which are like online fingerprints, and unique visitors are counted only once no matter how many times they visit the site.

USER SESSION - The session of activity that a user with a unique IP address spends on a Web site during a specified period of time. The number of user sessions on a site is used in measuring the amount of traffic a Web site gets. The site administrator determines what the time frame of user session will be (e.g., 30 minutes). If the visitor comes back to the site within that time period, it is still considered one user session because any number of visits within that 30 minutes will only count as one session. If the visitor returns to the site after the alotted time period has expired, say an hour from the initial visit, then it is counted as a seperate user session. This is another good indicator as to the quality of the website. THe higher the time spent the better.

VISITOR - Visitors are simply Unique Visitors that come to a Web site more than one time in a specific time period. The visits a particular site gets will always be higher than the unique visitor number for that reason. A high ratio between the Unique Visitors vs Visits is usually an indication to the quality of the website content. The more visits, the higher the quality.