it takes existing bandwidth, it doesn't charge them per load or anything.
the point being that most servers these days have so much bandwidth and images on average are pretty small.. it doesn't actually affect anything most of the time. i understand it for like H!O because they're privately owned and have a large volume of HUGE images and decently heavy traffic/usage for a website their size, but most places (even privately owned like my own website) won't be affected at all even if like a few hundred people hotlink some of my large images.
in general it's a good view to have because you never know, but the truth is it's mostly a 10-years-ago problem that these days is an almost imaginary threat (when it comes to images or any file under, say 5mb). Ameba should be equipped to handle all sorts of bandwidth requests for a website with as much traffic as they have, is all. and if they're not, that's not good for them.
more than likely they do that so that people might instead share the link and people would be forced to click to their site, thus providing even more traffic.
there goes my attempt at bringing things back to being on-topic.