10+ checkins in 12 hours! Next up: tweeting that you unlocked this Overshare badge?
As the badge subject implies, simply check 10+ times over a 12 hour time period to get this badge.
Tip: Be prepared to go overkill on this one and checkin extra times. Also you need to give 15-30 minutes between checkins sometimes.
Tip:
An easy way to get this badge is to go shopping at a mall for a day and checkin to all the store locations while shopping.