In many advertisements, people's clocks are set to 10:10.

In many advertisements, people's clocks are set to 10:10.

Look at a few ads - see for yourself! Why do they do this? Display clocks are set at 10:10 because the clock hands make a "happy" face which is pleasing to the eye. Advertisers are hoping people will associate that goodwill with the product they're trying to sell. It's the same reason attractive, smiling people are placed in many ads.