Youtube and other google apps don't support IE6, not to mention many other big traffic web apps and web sites (including 37signals apps).

IE6 has around 7% marketshare according to this: http://www.w3schools.com/browsers/browsers_stats.asp

Not supporting it is like telling one in fourteen of your customers you don't want their business. This seems like a bad idea, unless of course you have non-financial motives, such as wanting to kill off IE6 by not supporting it and driving it into oblivion.

Those are general stats, you need to look at your personal stats which might be at 0.5% or 65% and decide from there, not based on these kind of sites. Making your site work on IE will require tons of hour of work and therefor money. It'll also just not work for HTML5 apps, unless you have a second version of your site coded in flash. Make sure it's worth it.

You can't get meaningful stats unless you start out supporting IE.