While not absolutely everybody picks "3", most people do. Don't believe me? Check out the statistics below. While you're at it, fill in your own results.
One of the first explanations I heard for this phenomenon is that "3" has more curves to it than the other numbers, and is thus more attractive to the eye. To test this theory, I started randomly displaying the numbers in Times Roman (a nice, curvy font) to half the visitors, and in LCD-style (no curves) to half the visitors. If it were true that the curves were causing the effect, we'd expect that people who saw the LCD-style wouldn't prefr "3", while those who saw the Times Roman-style would. What were the results? You be judge:
| LCD | Roman | |
| 1 | 4384 | 4577 |
| 2 | 11959 | 11731 |
| 3 | 19038 | 17698 |
| 4 | 6499 | 6513 |
I would like to know if it worked for you, so I can keep updating my data. What number did you pick?