But in this case we're talking about a logo that's going to appear a few pixels wide on all clients - there's really no incentive to add the overhead of a large file transmission (not to mention the requisite client-side processing).
In a everything-is-made-of-marshmallows ideal world, yeah, bandwidth is not an issue, nor is site load time, and client-side CPUs and RAM are infinite. In that world I too would transmit everything, no matter how minor, in vector form. We do not live in that world.
The YouTube favicon.ico is 318 bytes long. I threw together a crappy SVG mockup of the logo with absolutely no size optimization, and it clocks in at 429 bytes. When gzipped, they clock in at 233 and 248 bytes, respectively.
If you're worried more about the 15 bytes than about compatibility, then just have the logo scale up and use it for your main logo as well; it should actually save bandwidth that way.
Something that people often forget when dissing vectors and SVG in particular, is that they're _scalable_ - so you can use the same version everywhere. So, you send the logo SVG once, and you could use it for the main logo on the homepage, smaller footer logo on the rest of the site AND for the favicon, because it'll scale. Browser just downloads one SVG file once, instead of 3 different bitmaps. Obviously, this is in everything-is-made-of-marshmallows ideal world where Internet Explorer doesn't exist, but hey.
Technically SVG is scalable, but not in practice. Small icons need different design than large icons, and SVG doesn't solve that. Look at fonts, they have hinting system to indicate changes for different sizes. Without similar system, SVG can't produce icons that truly are scalable. It's especially important in small icons like favicon(16x16px) which I believe will be hand drawn for long time.
I think that Apple does resolution independent icons by embedding several bitmap versions with a vector version in their icon files. That's the way to go in desktop applications, but similar system would produce too much overhead without significant advantage in web.
True, although the hinting is mostly just used for when things get tiny. SVG works well from sizes from 32x32 up to infinity, which is fairly impressive, I think.
Why should anyone be telling me what format decisions I make in the end? If SVG is right for the job, I'll use SVG. If it isn't, I won't. We do have a choice, here.
