True IE6 market share?

hi.

i was looking at the necessity to continue to code hacks for ie6, by looking at its current market share.

but i see big diffs between different online sources, such as here:

http://www.w3schools.com/browsers/browsers_stats.asp

which says 12% - which ain't much, so i may start abandoning ie6 hacks

but here it says 24%, which means ie6 hacks are still necessary.

http://marketshare.hitslink.com/report.aspx?qprid=3&qpcustom=Microsoft+Internet+Explorer+6.0

http://marketshare.hitslink.com/browser-market-share.aspx?qprid=2

how can these two sources have such different results?

which is right?

naturally, ie6 suks and i hope it dies a quick death.

hard to believe anybody is still using this ancient browser.

how can these two sources have such different results?

which is right? They might be showing the statistics of the visitors of their site.
Basically, if your markup is valid (http://validator.w3.org/) and semantic (http://boagworld.com/technology/semantic-code-what-why-how), you don't have to use excessive hacks to any browser.