The overall market share of IE6 is 48% IE7 is 31% Firefox across all versions about 14% That will give you a better idea. Obviously the number is highly differ

The overall market share of IE6 is 48% IE7 is 31% Firefox across all versions about 14% That will give you a better idea. Obviously the number is highly different for technology related sites. Example: I remember a popular tech blog mentioning that their firefox users were over 50%. So it really depends on your audience as well. Hope that helps.