The possibility that the photo contains a portrait of an attractive individual, those get the most viewings. Right behind that is spectacle, just as in real life. I guess people are drawn to promise of spectacular things. So bright and flashy colors might attract a few more. For example if i upload a pic of a dragonfly and the thumb is the resized full image, less people will look at it than when i cut out a portion of the pic (f.e. the head) and use that as a thumb. But this only means you trick people into looking at your pic, so i think everyone should just use the resized full image as a thumb. But who would listen to me... sigh lol ;o) So its either: 1) Actually make spectacular shots. 2) Trick people into thinking your shot is spectacular. 3) Dont give a shit and focus on what you like (recommended lol). Have a great day, Jeroen