In general, advertising doesn't work on the Web, a fact that has been clear to usability researchers since 1997. Users ignore ads because they are contrary to the Web's basic imperative, which is to let users go where they want and get their information needs instantly gratified.
From the beginning, it was also clear that this indictment of Web advertising had two exceptions:
Classified ads work because as far as users are concerned, they are content , not advertising: people actively seek out the classifieds when they are looking to buy. This explains the success of eBay, Monster/HotJobs, and many such sites. The superiority of Web classifieds portends dire times ahead for traditional printed newspapers, as their most lucrative income source continues to migrate online.
Search engine ads work because search engines are the one type of website that people visit with the explicit goal of finding someplace else to go. Thus, if users see an ad for what they're looking for, there is a high probability that they'll click that ad. Advertisers can satisfy a user's immediate needs because they target ads based on the user's query terms. (This also explains why ads on search engine homepages don't work: it's impossible to target the ad to the user's current quest until the server knows what that quest is.)
Both are examples of request marketing: prospects have explicitly asked for the promotions they are being shown, as opposed to having unwanted messages thrown at them.
Text-only ads on search engines have become particularly successful in recent years, and non-search sites are now experimenting with this format in hope of replicating that success. However, it's doubtful that their efforts will work because non-search sites lack the equation's crucial element: users' single-minded goal to leave the site as quickly as possible.
From Banner Blindness to Box Blindness?
Text-only ads might continue to work better than traditional graphics-based ads for some time to come. Web users have long exhibited strong banner blindness and avoid anything that looks like an advertisement. Text-only ads don't resemble the designs that people have trained themselves to screen out, and the resulting visibility surely contributes to the success of text-only ads.
Also, text-only ads benefit from a temporary novelty effect, as does any new advertising format that people have not yet learned to ignore.
Over the long term, however, the novelty effect will obviously fade. Users might also develop box blindness, ignoring little text boxes just as they've long ignored banner-shaped areas of the screen. Thus, text-only ads are not guaranteed a bright future outside their native search engine habitat.
Text-only ads might have one durable advantage: because they're a low-end media format, users might take them more seriously. Being forced to express a message in a few words concentrates the advertiser's mind, and probably leads to more communicative ads that are better focused on explaining how users will benefit from the product or service.
Although there is no inherent reason that you can't use text for mindless chatter -- like "where do you want to go today?" -- there is no way users will click on such ads. Ignoring users' immediate needs is certain death on the Web.
Companies that run rich-media ads that ignore user needs can delude themselves into thinking that they're "promoting the brand"; in reality, they're simply being ignored because they don't connect with people's needs. The text-only format more clearly exposes content-free messages as useless, however, and thus might save advertisers from the bad instincts they honed on old media.
After ten years of watching Web users, one clear conclusion is that they are utterly selfish and live in the moment. Giving users exactly what they want, right now, is the road to Web success, and having to write small boxes of text encourages advertisers to travel it.