Saturday, December 30, 2006

Making advertising accessible to the visually impaired

In the United Kingdom, there are currently around 380,000 people who are registered blind, and a further 2 million people who have sight problems or are visually impaired.This may only be a small percentage of the UK's population, but can advertisers really afford not to target this percentage?With today's technology and internet standards, XHTML and CSS are perfect for designing accessible websites for users who are blind or are visually impaired.

By following the W3C guidelines, it is possible to develop a website that is accessible to all users. A major problem in the internet marketing world that hasn't been addressed is accessible advertising There are many forms of advertising on the internet e.g. adsense, banners, buttons, sky scrapers etc. But are they accessible? The answer in most cases is no.Google Adsense is not accessible due to the fact that it uses the iframe tag and JavaScript, which prevents many screen readers and accessibility software from reading and interpreting the content. This is evident on Google's Accessibility Search, which is designed specially for disabled users e.g. visually impaired.

If you do a search, you will find that there is neither AdSense nor Sponsored Listings. Organic search, therefore, represents one very good way at reaching this audience.Not having accessible advertising inevitably means potential users are excluded from witnessing the adverts. It may be only a percentage of potential users but it represents a non-trivial demographic with appropriate spending power and the rights to the same web experience as any other web user.Banners or other forms of advertising which use graphics tend not to be accessible to visually challenged users.

Most information displayed in the graphic is completely lost when viewed by a text only browser. You can in some cases assign an alt attribute, but how effective are alt attributes? The correct way would be to provide a link to a long description of the graphic with the longdesc attribute. It may be provide to be impossible to convince sufficient publishers and merchants to alter their websites and media plans to include this longdesc tag.

Many sites still refuse to adopt new standards such as XHTML and CSS.So what is the solution for advertisers who care about that small but important percentage?At the moment, there is a form of search advertising which has blossomed and it consists of users registering and selling text link adverts on their website. This is of course against Google's Webmaster Guidelines and should never be performed. Google sees link buying akin to vote buying.

However, the technology behind the practise could be developed further and into a form of accessible advertising. Currently, publishers place a small piece of code onto their webpage where they would like the text links to appear. This piece of code then queries a database and displays links for the merchant who purchased the links.

This method allows automated user agents – such as search engines – to detect and follow the links whereas JavaScript or iframe alternatives would fail to be readily accessible.A possible solution to the advertising accessibility problem would be to use this methodology but make sure the links, or adverts, were detectable to Braille browsers, screen readers and other accessibility software while excluding the links from search marketing.In January 2005 Google, Yahoo and MSN Search (now Live Search) introduced a new link attributed designed especially for excluding links from search algorithms.

The "nofollow"attribute is added to anchor tags specially to tell the search engine that although the site is linking to another site (the publisher site is linking to the merchant site) it is not a "vote"which the search algorithms should consider. The "nofollow"attribute was introduced to battle comment spam on blogs but is easily adapted to "algorithm free"text advertising. In fact, the code could also be used to display graphic links with the longdesc attribute in place from an advertiser who took the time to add it.

As the adverts would not being used to gain PageRank or manipulate search algorithms then tracking code could be added to them and their success could be measured. Metrics like ROI and CPA could be factored in.This method of advertising may be a cure for some of the advertising accessibility problems.

There would still be obstacles to over come. For example, the "small piece of code"added to the publisher's websites is almost always a PHP Include or the equivalent. Sites unable to publish content in this way could not participate. There are also security concerns for the publisher to mull over.


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