C

Click Fraud -

Clicking ad banners without any intention of purchasing the product. Click fraud is done to make an ad campaign appear more effective.

Click Through -

A click on a link that redirects the user to another website.

Click Tracking -

Scripts (a program written in a programming language) to track users coming into and going out from a website.

Cloaking -

A method of delivery that changes which page is displayed depending on the user requests. This process is used by unscrupulous webmasters to deliver highly optimised pages to search engines while end users see a different page. Such practice is considered spam by most search engines and if caught can result in being banned from the search engine.

Comment Tag -

HTML terminology. An HTML tag that is invisible to end-users, but can be picked up by search engines. Comment tag was used earlier for getting better search engine results, but this tag has no use now as almost all search engines ignore comment tags.

Content Management System (CMS) -

A CMS is a computer software system for organizing and facilitating collaborative creation of documents and other content. A content management system is sometimes a web application used for managing websites and web content. Joomla, Drupal, PHP Nuke are examples of popular CMS.

Counter -

Program that tracks the number of impressions to a webpage.

CPA -

Cost per Action. The amount paid by the advertiser when a certain action is performed by a user.

CPC -

Cost per Click. The amount paid by the advertiser when a link is clicked upon.

CPM -

Cost per Thousand (M is Roman for 1000). Amount paid for every 1000 views of an advertisement.

Crawl -

This is the process by which a search engine indexes web pages in its database. Please refer to spider for more information.

Crawler -

A robot sent out by search engines to catalogue websites on the internet (also called a Spider). When a spider indexes a particular website, this is known as 'being spidered'.

Cross Linking -

Multiple sites all linking to each other. Expand more.

CSS (Cascading Style Sheets) -

These are used in web design to allow for quick changes to a websites look and feel. For example, you can change the colour or font size of every page by changing your style sheet without having to make the changes to each page.

CTA - Content Targeted Advertising -

It refers to the placement of relevant PPC ads on content pages. E.g. by subscribing to Google's Adsense program Google may place your hotel advert on other travel relate websites You pay a cost for every time a user clicks on your advert, and a small commission goes to that originating website. See Click Fraud

CTR -

Abbreviation for 'Click Through Rate'. It is a ratio of clicks per impressions in a PPC campaign. E.g. if a site gets 1000 impressions and 50 users click the ad, then the CTR is 5%. CTR is mainly used to find out the effectiveness of a PPC campaign.