Tag Heuer, Breitling, Rolex, Timex... they all compete against each other to position their brand name at the very top but even they agree upon one common ground! All the watch manufacturers set the time to 10:10 (10:09 in some cases) for advertisement purposes. 

But do you know the reason behind this phenomenon?

Apparently, the 10:10 time gives the appearance of a "smiley" which strikes a chord with the people

Earlier, watch manufacturers used 8:20 as the time, for advertisements. But they realized that it looked more like a frown, and that would dissuade people from buying it. 10:10 symbolises happiness!

Source: Rediff

At 10:10, all the attributes of the watch are clearly visible

Brand name, type, date and other special qualities of the watch (like secondary dials) are more pronounced as there is no overlap between the hands.

Source: Pinterest

The angle made by the hour and the minutes hand also provides an underlining effect to the brand name (enclosing the brand name and thereby attracting attention). 

Source: Louis Pion

This also explains why the seconds' hand is usually set to '35' so that the aesthetic beauty, arising out of the angles made, stays intact. 

Source: Yaabot

Symmetry reasons

10:10 assures vertical symmetry in the face of the clock. But the same could be achieved with the time being set to 8:20 or 9:45, then why do manufacturers prefer 10:10? 

Source: Breitling

When the clock is at 10:10, the positioning of the hands creates a "v" symbol, which symbolises victory

It could be said that manufacturers use the "victory" quotient to tap into people's emotions. This is plausibly one of their emotional marketing gimmicks. 

Source: Blogspot

Well, now you know!