With css being more widely used in most of todays websites users of Internet Explorer 8 and below will have difficulty seeing your site as it is intended.
As the market percentage of users still using IE8 or below is becoming extremely small it is quick and easy to notify these users that it’s time to upgrade or that your site won’t work properly.
Place the following into your sites index page, it is rendered as normal html for users of IE, other browsers simply ignore it.
<!--[if IE 6]> You appear to be using IE6, You should consider updating or switching to Firefox / Chrome. <br /> Our website will not function correctly unless you do so.<![endif]--> <!--[if IE 7]> You appear to be using IE6, You should consider updating or switching to Firefox / Chrome. <br /> Our website will not function correctly unless you do so.<![endif]--> <!--[if IE 8]> You appear to be using IE6, You should consider updating or switching to Firefox / Chrome. <br /> Our website will not function correctly unless you do so.<![endif]-->
