My argument was about anonymous questions, Ellotris. Of course, it is probably not feasible to determine if someone forgot to select a best answer of if they simply didn't find any answer suitable for their need.
But about anonymous question, I don't even know if a anonymous user can select a best answer at all.... Apparently there is zero anonymous question where the person who asked selected a best answer later. Thus, I've made in my mind a system where anonymous question would be encouraged to be answered, since now we would have a best answer to it. I would particulary not be inclined to answer a complex question if it was made by someone who can't or will not select any best answer at all, no matter how good they are.
Of course, we could adjust the amount of points received on this system. I also would like to see a special note telling that this best answer was picked by a system