Wristwatches

When the first wrist watch was made in 1868 they were generally reserved for women. Gentlemen, who carried pocket watches, claimed they would "sooner wear a skirt as to wear a wristwatch".
Before wristwatches became popular in the 1920s, most watches were pocket watches which were introduced In the 16th century. The main feature of these watches was obviously to keep time but during World War 1, soldiers on the battlefield found using a pocket watch to be impractical. So they attached the pocket watch to their wrist by a leather strap, which completely changed the belief that wristwatches were classed as a women's items.
Since then watches have become more advanced and new technology and applications have been combined into the one device. This includes alarms, water resistance, compasses, altimeters, and thermometers. Some of the higher end sport watches even include a "heart rate monitor.
The reason i believe that wristwatches are the best consumer product is mainly because they are now also a fashion item as jewelry or as collectible works of art rather than just as timepieces. This has created several different markets for wristwatches, ranging from cheap but accurate watches to expensive watch that mainly serve as personal decoration or as examples of high achievement in small precision engineering.
As new technology is introduced, it will be added to the simple idea of a timepiece on your wrist, which is why i believe there will always be a successful market for these items.
Shaun T