For example, the other day I got an email with, "Start the New Year with Your Sole Mate" as the subject line.
You could actually open the message and learn it was sent by some money-grabbing dolt who doesn't know their homonyms, or, like me, you can just assume it was a thoughtful heads-up for a sweet new dating site.
Below is a sketch of where I'm assuming the message's links would've sent me (click for larger version):
Can you find all 17 footwear puns? (Admittedly the number is a bit dependent on how you count the puns, but I hope you get a kick out of it regardless.)