Chip,

You make a valid point. If you're not exceeding your hosting bandwidth, CDN will indeed be an additional (but modest) expense. However, with CDN, you're buying a different kind of bandwidth that can enhance performance and scalability. In other words, you're paying for an extra that standard hosting doesn't offer. So the question is how important that extra speed and scalability are. With Google now taking speed into account for page rankings, those few dollars could be buying you a lot.

Just my .02 worth...not a plug for our service but observations on CDN in general.

Mark