You might come across videos on YouTube which have blank or terribly looking thumbnail image. Usually, when a video is uploaded, YouTube automatically picks the center frame and sets it as a thumbnail image. Users have no really control over these thumbnail images, except for some smart tricks to get their desired thumbnail image, but most of us don’t have the time or patience to practice those tricks.
YouTube realized this problem, and they’ve made it possible for users to pick one out of three thumbnail images. YouTube captures three thumbnail images at x/4, x/2 and 3x/4 seconds and video owners can choose any one of these thumbnail images by clicking on “Edit Video Info” button next to their video on My Videos page.

wrote, on August 7th, 2007
This is a good one! So now people can choose a better view for thumbnail which can make there video more attractive!
wrote, on August 9th, 2007
Hey great information, I am looking for this for my videos.
wrote, on August 10th, 2007
who is that guy in the pic!! Lol
wrote, on August 28th, 2007
Other video sharing sites like metacafe had this feature since a long time
wrote, on January 2nd, 2008
can any one help me PLEASE! my thumbnail is not changing and it been about 2 to 3 dayz its very annoying plz help
wrote, on March 28th, 2008
I uploaded two videos, one today and one yesterday, and neither has the option of selecting a thumbnail to represent it. All I see are three empty thumbnail frames from which to choose. How do I get the thumbnails to show?