An overview of the major types of web advertising

More and more innovative types of advertising are coming into existence as the Web matures, so this is not meant to be an exhaustive list. However, it covers all the main types of advertising in use today.

Banner Ads
Despite widespread concern about the effectiveness of banner advertising, this is still a popular form of web advertising, perhaps because it's so familiar.

A banner ad is a graphical bar or button containing text or graphics designed to attract a viewer's attention and induce an action (usually, invite the viewer to click through the banner and visit the advertiser's site).

Banners come in all shapes and sizes, although some clear standards have emerged. For instance, the 468x60 pixel banner is a very popular size, as is the 234x60 banner (half the size of the larger banner, so two fit into the same space). Here's a list of banner sizes to help you.

Banner ads can be static or animated. The most popular graphic format for banner ads is GIF format. Most banner ads are sold on a CPM basis or on a CPC basis.

Some sites show more than one banner ad per page, and some even go so far as to use a little software program to rotate banners every few seconds while a visitor remains on a given page.

Text Ads
Popular in newsletters and RSS feeds, and on many sites, text ads are probably the dominant form of online advertising today. After all, for some products, a few well-chosen words are worth a thousand pictures! A text ad consists of a few lines of copy together with a link or an email address for action. Text ads can be priced like banner ads on a CPM or CPC basis. It can be difficult to track how many text ads have been shown on a site, so many sites choose to quot;hide" a 1x1 pixel transparent graphic right next to the text ad and count how many times the graphic is loaded as being the number of times the text ad was loaded. Either that, or they use some other mechanism (e.g. JavaScript) to "serve" the text ads, and an impression is counted each time that mechanism delivers a new ad.

Probably the most well-known example of text ads is Google's Adsense program, which delivers contextually relevant text ads (ads targeted based on the content of a page) and is in use by hundreds of thousands of sites worldwide.

Text ads in newsletters are usually specified as a number of lines, with a maximum number of characters per line. For instance, a site might offer ad space in its newsletter by specifying a maximum of ten lines of text and 65 characters per line.

Interstitials
You'd think that marketing types had nothing better to do than dream up swanky terms. Interstitial ads are nothing more than ads that are shown in the transition between two pages of a site. So you click on a link on Page A, but instead of going to Page B you arrive at an intermediate page containing the sales pitch (and - hopefully - a link to Page B somewhere on the page!). Interstitials are gaining in popularity with advertisers since they offer an almost unlimited amount of space to pitch a product. Many site visitors find interstitials irritating, and they also increase site loading times.

Pop-Up Ads
According to many webmasters, pop-up ads are the most annoying type of advertisement... although there is little evidence this sentiment is shared by the larger Web community.

Pop-up ads consist of a small window that "pops up" over the main browser window when you enter a site (and sometimes when you leave it, a favourite tactic of adult sites). The pop-up windows can contain anything: text, graphics, a form to collect information or email addresses, even a little game.

There are two downsides to pop-up ads, one for webmasters, one for advertisers. From a webmaster's point of view, pop-up ads wrench control of the browser away from their own page, and some badly-written pop-up ads may also crash certain browsers, leaving a permanently bad impression in a visitor's mind. From an advertiser's point of view, most pop-up windows can be minimized (hidden behind the other windows) with relative ease, so if the pop-up window is being used to rotate ads on a time basis, your advertisement may not even be visible but you'll still be charged for it!

Opt-In Mailing
An advertising type that is rapidly becoming popular, opt-in mailing consists of sending an email message to a "pre-qualified" list of people i.e. an audience that has expressed an interest in receiving information on a given topic.

Some sites sell their lists of newsletter recipients to advertisers, but most prefer to keep the email addresses secret and distribute the ad on the advertiser's behalf.

If you want to advertise using opt-in mailing, approach mailing lists with caution and check that they are being offered by a reputable firm. Some unscrupulous companies think nothing of "padding" their lists with the names of people who have no real interest, but who have been virtually press-ganged into joining.

Opt-in mailing is not the same as SPAM. SPAM is another word for bulk mailing, and involves sending a message to people whohave never shown any interest in receiving it. SPAM will destroy your business. Some companies claim to be opt-in whereas they are actually selling SPAM services. In general, don't expect to pay less than $0.20 per name for a real opt-in mailing - and many are around $0.50 per name or more. SPAM services sell their lists ridiculously cheap, for instance $250 for 10 million names. Don't get caught out!

HTML Ads
HTML ads combine graphics and text with other HTML elements such as pull-down list, check boxes or forms. These can be very effective ingetting traffic, but are much harder to serve and track, and generally require sophisticated software to run properly.

Rich Media Ads
Rich media ads make use of multimedia elements such as sound, animation (often using plugins such as Shockwave or Flash) and Java/Javascript to drive the message home. Great for advertisers, less good for webmasters since the premium for rich-media ads is not particularly high, but the extra load time and annoyance can be considerable (you'll lose your audience of visitors surfing from work on audio-equipped PCs for a start if your site suddenly blares out music!)

Hybrid Ads
Hybrid ads combine aspects of other advertising types, such as text and banners, to make a more effective pitch to visitors.

Sponsorships and Partnerships
Not a different advertising type, exactly, but a different way of approaching advertising; sponsorships and partnerships usually involve integrating the advertising more fully into the body of a site. Sponsorships, when done well, can be both discreet and effective. Many sponsorships take the form: "Site brought to you by Sponsor" or "Sponsor's guide by Site"