What is a mayor?
The mayor is the user who has checked in on the most days at any venue over the past two months. Being the mayor of a venue is mostly a symbol that you’re a frequent visitor and have established a connection with the venue.
Some venues choose to recognize their mayor by offering “mayor specials.” Others have been known to post the picture of the mayor somewhere in the venue. Zagat Buzz has recently started a “Meet the Mayor” feature on their blog.
Mayor races can often become fiercely contested. In order to become mayor, you must have checked in on more days than the current mayor; tying with the mayor is not enough to oust them. You can see how many times the mayor has checked into a venue by mousing over their photo on the venue page. It’s often a happy surprise when you find out you’re the mayor of a venue because the number shown on their photo is the total number of checkins instead of the number of days checked in over the past two months.
All of your mayorships are shown on your profile page. When you reach ten mayorships, you earn the super mayor badge the next time you check in at one of the locations where you hold the mayorship (this is often confusing, since it’s not the checkin where you actually earn the tenth mayorship).
In order to be a mayor, you must have a profile picture attached to your account.
Occasionally when duplicate venues are merged the mayorship is awarded improperly to someone with fewer checkins. This issue is temporary and sorts itself out the next time anyone checks into that venue.

Pingback: FAQ: I have more checkins; why am I not mayor?