The first thing to realise about advertising on the Internet is that there are many different approaches which can be taken, there are banner ads, button ads, interstitials, and drop down windows. Some are worth using, others should be avoided, Fortunately, however, advertising on the Internet has at least developed a number of standards with regard to advert size.
Different sizes and types of advert – The most frequently used type of advert on the Internet is the banner ad across the top of a page, down one side, or simply a small button.
To make the incorporation of online adverts, or Interactive Marketing Units as they are now called, into web sites easier the Internet Advertising Bureau, the IAB, have established a set of guidelines for the size of online adverts, they are as follows:
- Full Banner – 468×60 pixels
- Full Banner with Vertical Navigation Bar – 392×72 pixels
- Half Banner – 234×60 pixels
- Vertical Banner – 120×240 pixels
- Button 1 – 120×90 pixels
- Button 2 – 120×60 pixels
- Square Button – 125×125 pixels
- Micro Button – 88×31 pixels
There are also two new much larger vertical online ad formats, refered to as Skyscraper Units, they are:
- Full Skyscraper – 120×600 pixels
- Wide Skyscraper – 160×600 pixels
In addition there five new large rectangular ad formats, these are also the standard for ‘pop-ups’, they are:
- Square – 300×325 pixels
- Square – 250×250 pixels (this format utilises Java)
- Vertical Rectangle – 240×400 pixels
- Large Rectangle – 336×280 pixels
- Rectangle – 180×150 pixels
Banner adverts come in a variety of graphics formats. The most widely used is the GIF format. A GIF image can be either a single image, or a series of animated images. Occasionally JPEG format images are used, and new interactive multimedia formats now include Java and DHTML banners. When using any of these new formats remember that there are still a significant number of Web users who do not possess systems which can view ads created in these formats.
It should be remembered that most sites which accept banner ads will also place a size limit on banners, of between 10-15k. Use 5 bit graphics to reduce file size or use GIFbot (http://www.netmechanic.com) to analyze your GIF or JPEG images, GIFbot will also produce smaller-sized alternatives which make better use of compression and colour.
Rich-media adverts are becoming increasingly popular and are gradually replacing one-dimensional graphical ads with HTML-enhanced ads that enable readers to interact with the ad. These interactive ads use quite a lot of bandwidth, but seem to attract more click-throughs than the static traditional adverts.
Just as online advert sizes are becoming standardised so the positioning of ads is also becomiong standardised. The theory of ad positioning on web pages has drawn heavily upon extensive research done for print advertising and much of the terminology is shared in common.
A web page is basically divided into two parts, the division line being known as the fold. The area above the fold is regarded as prime advertising space and is defined as being from the top of the page to the bottom of the screen. That area of the page which can only be accessed by using the scroll bar is referred to as being below the fold, and advertising here commands much lower prices.
The page area above the fold is divided into four quartiles, upper right, upper left, lower right, and lower left. Studies by advertising psychologists show that the best response comes from ads placed in the upper right quartile, with the next best response coming from an ad in the upper left quartile. Ad prices reflect this view.
Other types of advert
Other types of advert currently in use include pop-ups, and interstitials. Pop-ups are those little browser windows containing an advert which appear when you visit a site. Interstitials, are full pages of advertising which appear when you think you are clicking through to another content page, they usually either refresh automatically returning you to your original destination page, or use a link button to achieve the same thing. Both these forms of advertising are extremely annoying to the user and are probably best avoided.