A selfie/photobooth station would be so fun! Maybe you could get some silly props to go with it? Ask folks to enter with a hashtag via Instagram, and you'll start to generate some natural word of mouth marketing through their social networks, too. 😉

As a heads up, we're hosting a Q&A next week on the topic of communicating with customers during the holidays with one of our product marketing leads. If you have questions about how to use emails/ giveaways/ coupons, etc., feel free to add them here: How to Effectively Communicate with your Customers during the Holidays

This is a fun thread - can't wait to hear more ideas!

Here are a few things I have done.

Balloons of Savings - Blow up a bunch of balloons (with helium) and insert a slip of paper with discount or prize.  Everyone who makes a purchase gets to pop a balloon.

Ornament Smash - Same concept just with Ornaments.

Can/Cash - Bring in a food item and get a $ off your purchase.

Double Points - If you use Square loyalty you could change your star settings and give them double points during a time frame.

Bounce back Coupon - We created a business card size coupon that we give out after each sale.  

To add to the Selfie thing,  We did a Win a Harley for your Selfie with a local radio station.  They brought the Harley here for a day and people had to come in and take their selfie with the bike to register.  Anyone that came in and did it we gave them a discount.  Great promotion.