Apple did extensive research in both formats. The only advantage was in looking at video made for the 16:9 HDTV units. Movies are an even wider format and until HDTV, television shows were 4:3. In almost every aspect, people were more comfortable with the 4:3 screen. Books were easier to read, web pages looked better, and most important, it fit the hand better. This was not a cost issue, it was a comfort issue.