Some things that make youtube.com loose money.

Youtube is know for the amount of data it has every day which is translated into big amount of cash spent for Internet Bandwidth. They are estimated to loose $1 Million dollars per day !

What they could do to save some money.

-Avoid auto reproducing videos when opened.
-Load videos from cache of visitor instead of having to reload If I happen to want to see same video after it has just finished.