Advertising on the Internet is here to stay, and love it or hate it, good advertising is certainly preferable to bad advertising. One thing that is important for advertising is that it follow the Principle of Least Surprise, which I recently discussed as it pertains to software application development. In online advertising, this principle can be applied in a couple of ways

First, recognize that advertisements in general are an annoyance to users. Given the choice, 99.3% of users (remember, 75% of all stats are made up on the spot) would do away with advertisements if they could do so without an consequences. Further, for every cool web application or site on the internet, there are 10 more that are copycats with nearly the same feature set (or will be, in about 6 months after one grows popular). Thus, annoying users too much can have grave consequences.

Second, recognize that users associate products and brands with advertising even if they don’t click on the ads. I know, this is crazy talk since so many advertisers think the only thing worth measuring on the inter webs when it comes to ads is clicks, but I’ll let you in on a secret:A lot more users see the ads than click on them. Anybody who’s been online for a few years remembers the X10 product because of their annoying pop-under ads. For a while there, you couldn’t follow 3 links from anywhere online without an X10 ad popping under your window. I don’t think I ever once clicked on one of those ads, but I certainly closed a lot of them, and now X10 is forever etched in my memory in association with “annoying.” Now, X10 may consider that a success. Better to be remembered as annoying than never heard of. But if you’re Microsoft or Coca-Cola or IBM, folks already know about you, so adding associations with negative emotions is not a good thing.

So what does this have to do with the Principle of Least Surprise, which is mainly related to user interface design and software usability? Consider certain modes of advertising, such as pop-up ads, interstitial ads, and ads that take over the user’s screen for some period of time. Each of these prevents the user from doing what they wanted to be doing, which almost by definition causes annoyance. What’s more, often these ads make their entrance after some delay, so the user though the page had loaded and thought they could go ahead and start reading/scrolling/navigating an then BAM! in comes this ad to ruin their experience. Ads that are jarring to the user experience, that surprise the user and/or prevent them from interacting with the application, are violating the PoLS, hurting the usability of the web site/application, and the user is learning to associate the product or company that is responsible for the ad with this negative experience.

Likewise, in traditional non-intrusive ads, the PoLS applies to the experience the customer receives when they click on the ad. Consider an ad that offers a “Free Trial – Click Here” which is not at all uncommon. If the user clicks on this ad and is immediately taken to the “Download Trial” page, that is no surprise. It’s exactly what the user expected and it’s very likely that a fairly large percentage of the users who clicked on the ad will then proceed to download the trial software (a great many still won’t for various reasons, but not because they were surprised about where the ad took them). Now consider the all-too-common alternate scenario, where the user is taken to the company’s home page or to the product’s home page. Most home pages make poor landing pages for advertisements – the offer and call to action in the advertisement should be reinforced consistently in the landing page, and it’s unlikely that a company or product home page will be so designed to match any given ad. Further, the home page or product page will almost certainly include a link to “Buy Now”. This is good design – it’s important for users to be able to easily be able to purchase products from the site. However, if the user arrived at this page from an advertisement promising “Free Trial” and now the only prominent link they see on the page is “Buy Now”, they’re going to feel tricked. It reeks of classic bait-and-switch tactics. The user experience is going to be surprise, followed quickly by resentment and anger that they were tricked into clicking on something with the promise of a free trial only to be immediately asked to pull out their wallet and “Buy Now”.

Effective online advertising campaigns should consist of more than a text ad or banner that links to the home page. The most effective campaigns include a custom offer or call to action which must be tied into a landing page experience that explains and reinforces this call to action. If the ad promises a free trial, then the most prominent link on the landing page should be to download the free trial. If you remember the Principle of Least Surprise and optimize the user’s experience as they go from ad to landing page to wherever that takes them next, your users will have a much more pleasant experience, and even the ones who don’t buy today will at least retain this positive association with your company, brand, or product.