Google (starts?) browser sniffing on main page

toolbar annoucement only shown to IE users

[amznVibe]

I noticed that Google is now browser sniffing (via headers apparently because its not in the code using javascript) because only IE users without their toolbar are being told about the new Google toolbar.

I wonder how much more bandwidth that one extra line starts to add up to for thousands upon thousands of requests. Nice that they have such high visibility for such a sales pitch (though its a free product). Imagine what some advertisers would pay for that kind of advertising space!