First Round Capital has a great profile on the brand development of Harry’s (the guys behind Warby Parker).
I particularly like where they zagged to after Movember’s zig:

Last year, Harry’s launched National Shave Day on December 1 to much fanfare — riding on the coattails of another cultural facial hair phenomena: Movember. In doing so, they appealed their target market, and not only appeared timely, but prescient. After not shaving all month, men everywhere were in desperate need of a good razor.

“The holiday created more story around the brand. We had an event at our barber shop, put it on the web, promoted it on social media, and we watched the conversions explode,” says Morin. “When we tell stories that connect with people, it’s obvious. On National Shave Day we saw a 360% lift in traffic to the website.
Smart guys.