 <p>If you're the vendor supporting a web application which your customer insists upon using with IE6 rather than an updated browser, I'd say try to offer them upgrade incentives (e.g. lower support contract fees, a one-time renewal discount, or some "enhanced" feature set which would magically be enabled once they upgrade their lowest common denominator browser-wise).</p> <p>I'd agree with some of the previous sentiments mentioned about warning banners, they'd be annoying and useless.</p> <p>If the company is so big and/or bureaucratic that they are a hard sell in terms of upgrading, it might take years for them to get "current". A hospital I once worked for was just finishing an upgrade to Windows NT 4 while XP had already been out a year.</p> <p>Personally, if I had any influence over such a situation I would enclose with my annual invoice a very obvious raise in my support or dev fees substantially every year IE6 remains in use at the customer's site, while at the same time presenting them the attractively lower-priced option of upgrading their browser right alongside.</p>