According to [this](http://www.bbc.co.uk/news/technology-18440979) BBC News article, the online retailer [Kogan.com](http://kogan.com) has started with an added tax for the users who are still browsing there site with IE7.
Apparently the tax is set to be 6.8% which represents 0.1% for every month since IE7 was released.
Mr Kogan was quoted saying:
>"I was constantly on the line to my web team. The amount of work and effort involved in making our website look normal on IE7 equalled the combined time of designing for Chrome, Safari and Firefox."
Hmm... I wonder if this will catch on :)