Businesses generally use web services in communications and sales functions. As a result you'd expect the larger users to bend over backwards to make sure their sites worked with all major browsers, but many don't.
There are several kinds of costs to this behavior - costs that don't show on any corporate ledger but reduce the return the business gets on its web investment and may well create long term customer hostility.
Some examples of the problem, of course, are just funny: when Air Canada created its first public web site the mainframers in charge responded to the certainty that all users must be authenticated by creating a site you had to log in to with a user id and password in order to apply for a user id and password.
Fortunately that was more than ten years ago, today they express their concern for their customers by issuing electronic tickets as locked PDFs that can only be seen or printed if you have Microsoft's proprietary Verdana fonts installed.
Probably the most common form of this, however, is the web site that provides more information to IE users and doesn't give the non IE user any indication that something might be wrong. Browse the Transaction Processing Council's web site without IE on Windows, for example, and you'll be silently frustrated by search, ordering, "all results" tabs, and a number of other features that seem to work correctly with Mozilla for Solaris - and the same holds for the major sites run by Microsoft and HP.
A third form of this is at least upfront about the issue. For example ScotiaBank's "Rewards" site baldly confronts non IE users with a polite message explaining the error of our ways:
The browser you are using to access this new website is currently not supported. We will continue to update the site and add additional web browser support as soon as possible.
The site currently supports Windows®-based Internet Explorer® 5.5 or greater. The latest version of Internet Explorer is available free from Microsoft.
Customers wishing to place orders or make travel arrangements can contact our call centre at 1-800-665-2582.
And the call center, of course, is entertainment fodder for masochists.
So what are the costs of the Windows chauvinism exhibited in these kinds of IT behaviors? I don't know, but I'd sure like to. As you read this I'm actually skiing (or recuperating?) in Montana, but I'd sure like to know if anyone has real data - perhaps survey based?- on changes in customer attitudes arising from this kind of thing. Talkback or email, please.