Smoothie King is also offering free 20-ounce smoothies today when you use the chain’s Healthy Rewards app, and Red Mango is offering half-priced smoothies all day to celebrate the big day.

Celebrate National Flip Flop Day with a FREE 12 oz. Tropical Smoothie Cafe Strawberry Margarita Smoothie when you wear flip flops on Wednesday, May 31 from 2 - 7 p.m. at participating locations!

Smoothie King is offering a free pumpkin smoothie for Healthy Rewards Members from 8/31-9/2 when you take a fun, pumpkin-themed quiz on their website! Smoothie King is rolling out 5 pumpkin ...

Flip flop-wearing guests may visit a participating Tropical Smoothie Cafe for a free 12 oz. Sunrise Sunset smoothie on National Flip Flop Day. Drop in for a refreshing smoothie on May 28 from 2 ...

Branded smoothie kegs are free with the purchase of a smoothie six-pack, a combination of any six smoothies, as long as supplies last.

Tropical Smoothie Cafe is offering up some free fun in the sun for National Flip Flop Day. On Friday, June 14, customers who wear flip flops into a shop can snag a free 16 oz Sunshine Smoothie.