In traditional user-centred design, focus is on users’ needs and their use of the product, while marketing is left to the marketing department. On the web, usability and marketing go hand in hand. Whether commercial or not, a web site has to meet the need of its users and at the same time convince them to take action, for the objectives behind the site to be meet.
There are many reasons why advertisements don't work well on the Web, but it is most unsettling when an ad actually portrays something relevant to users and still fails. Why would this occur? Well, to start, we must consider why text ads work so well on search engines. Each user has a goal -- perhaps it is to learn about digital cameras, perhaps to purchase a book. In either case, users' attention is focused on whatever gets them to their goal; they ignore everything else. When users enter search queries, the targeted ads that the engine returns relate directly to what users are after. Hence, they look at and follow the ads. Indeed, such advertisements probably have an advantage over the plain search results because they show both that the advertiser is competent and has a direct interest in serving consumers.
Regular web users will almost certainly be aware of an increasing amount of ‘invasive’ advertising appearing online. A variety of methods are now being used to make online advertising almost unavoidable for the user.
It has long been acknowledged in the study of usability, that the usability of a product affects the associated brand identity. While study of usability is universal to any product design, it has sprung up with the advent of the world wide web. It is becoming more important of individuals and institutions to establish a strong on-line identity for themselves or their products.
Improving ‘brand experience’ online is not normally regarded as the primary goal of a usability strategy. In some circles usability and branding would even be seen as mutually exclusive, based on the assumption that successful branding relies on ever more garish visual design and an extensive use of animation, audio streaming, or whatever the latest cutting-edge technology might happen to be.
I recently have read a lot about the use of banner ads. My short answer is that they don't work. They might be useful for branding and image campaigns but they are not usable and users don't like them at all.
Text-only advertisements work far better than banners, but is this only due to their novelty? Search engine text ads will retain their superiority over time, but text ads on other sites will work only if they focus on directly meeting users' needs.