I come across YouTube links all the time in email, instant message chats, Facebook posts, on message boards… you name it.
I usually don’t mind these links, as I’m always up to hear a new band, laugh at a silly video, or see an awesome play from the world of sports.
What I do mind is people posting links then saying “[the thing I want you to see] is at 4:45 in the video”. So you have to click the link, then scroll through the video.
For over a year now, YouTube has supported deep linking to specific points in a video. To use it, all you have to do is add something like “#t=2m30s” (without quotes) to the end of the YouTube link.
Check it out in action: Pulp Fiction (regular link); Pulp Fiction (deep link).