There are many different sizes and formats for banner advertisements, with new types continuing to emerge as technology evolves. This article tries to help advertisers new to the field by explaining the kinds of banners currently being used in the media industry.

Many websites offer banner making software at minimal price, however if you require something professional, you should employ the expertise of a graphic designer. Once your advertisement is complete, you can purchase ad space by contacting websites direct, joining an ad network or browsing through a <a href="http://www.bidswamp.com">banner auction</a> website. However before you begin, you should at least be aware of your options:

Banner Sizing

Banners can be made to any size. The Interactive Advertising Bureau has set down voluntary ad unit guidelines for industry standard ad sizes including rectangles, pop-ups, buttons, skyscrapers as well as banners.

Just like technology, banner ad sizing continues to change with marketing trends. Members of the Online Publishing Association (OPA) have started to use gigantic ad sizes for enhanced branding effect. The new ad formats include a "pushdown", a "fixed panel" and an "XXL box", all described below.

Banner Functions

• Static banners - remain still, motionless and unchanging in the same place until the visitor exits the web page.

• Animated banners -incorporate movement and as a result attract higher click throughs than static banner ads. Generally in GIF format they are made up of a collection of images in one file that are shown in a specific order. The file can be looped to continue the movement or the banner can be made to stop after completing the cycle. Being able to show several files with varying data lets advertisers display more information than a normal static banner. To limit your load time, keep to a maximum of four frames. This will also enable viewers to read your ad before continuing to browse.

• Rotating banners - commonly used by highly trafficked websites, these ads alternate among different web pages within the site. A visitor might see numerous advertisements while remaining on the same page if a rotation has been set up to take place every 15 or 30 seconds.

• Scrolling banners - just like the modern billboard, a visitor will see different advertisements as ads are scrolled through every 10 to 30 seconds.

• Expanding banners - enlarge when clicked. Rather than being linked to the advertiser's site, the visitor remains on the same website. Viewers can then elect to expand the ad to find out more about the promotion. Some expandable webpage banners even have shopping cart functions where the user can make a purchase straight from the banner without even visiting the advertiser's website.

• Drop-down menu banners - enable viewers to click on the banner and select which page or website to visit before clicking through to the advertiser's site. Such banners contain a HTML code for the drop down menu. These are preferable to standard banners (which require visitors to click through and then navigate the relevant pages of the website if not satisfied with the landing page). Advertisers can use drop-down menu banners to lower costs by joining campaigns.

• Interstitials - open up in a new browser window as the viewer's destination page loads. Often interstitial ads will contain a streaming presentation, sizeable images and extra applets featuring display, graphics and even human interaction.

• Rich media ads - enable advertisers to combine sound with animation using Java, Flash or Shockwave. Whilst Java banners are more innovative, they do take longer to load, which may deter some users from viewing them. Shockwave and Flash load faster and are therefore more ideal for incorporating into rich media advertisements.

• Floating banners - fly or float around the page for up to 30 seconds after first landing on the page, often disabling mouse input. Although they have a high click through rate, some find these advertisements highly frustrating as they obscure visitors' view.

• Unicast advertisement - entails a video played like a television commercial usually running in a pop-up window. Viewers can click on the ad to visit the advertiser's website. The screening can last up to 30 seconds. Such ads also have a high click through rate.

The following ads are currently being tested by OPA members:

• Pushdown advertisement - these advertisements are basically expanding banners, enlarging to almost a full screen when a page loads. OPA requires this format to collapse after seven seconds after which users can click expand to read the campaign. However, some publishers such as Cosmopolitan have allowed advertisers to keep the ad expanded, requiring the viewer to close them (although serves were limited to one user impression per day).

• Fixed Panel - a band measuring 336 x 860 which seems set in the browser. As the user scrolls, the panel rolls to the top and bottom of the page.

• XXL Box - hence its name, this ad is colossal and is being tested for branding effectiveness. The 468 x 648 sized advertisements can accommodate several pages and video.

Although many ad formats and sizes exist, always remember to stick to the basic principles: avoid information overload, use an easy to read font, use alt tags to target surfers with their graphics turned off and keep the file size to a minimum to ensure fast loading. It also helps to link the ad to an appropriate landing page rather than your home page.

About the author:

Dita Bednar is a co-founder of Bidswamp, a banner auction website which helps advertisers and site owners connect to buy and sell banner space. Visit <a href="http://www.bidswamp.com">Bidswamp.com</a> to find and compare ad space up for sale.