Tropical Smoothie Cafe celebrates National Flip Flop Day annually on the third Friday of June.
CONTRIBUTED PHOTO FROM TROPICAL SMOOTHIE CAFE

There are no strings — or shoelaces — attached to this freebie Friday.

From 2 to 7 p.m. June 15, get a free limited-edition Sunshine Smoothie when you wear flip flops to any of the 600-plus Tropical Smoothie Cafe stores nationwide.

No coupon or purchase is needed to get the free special smoothie, which is a combination of orange, banana, pineapple and mango.

But the Atlanta-based chain's annual National Flip Flop Day serves as a fundraiser for Camp Sunshine, a retreat for children with life-threatening illnesses and their families located in Maine. 

“We started National Flip Flop Day as a fun summer event, but the ultimate goal is much greater than free smoothies,” said Mike Rotondo, Tropical Smoothie's chief executive officer, in a statement. “We’re raising money to help families who are facing life’s worst circumstances.”

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Since 2007, the fundraiser has raised more than $5.3 million for the camp, enough for more than 2,100 families to attend the camp for free. This year's goal is to raise $1 million.

Customers who make a donation can get a paper sunshine that they can customize and display at locations.

Making a donation also can equal savings.

Purchase a $5 Sunshine Key Fob and get a 5% discount on all Tropical Smoothie Cafe purchases at participating locations for the rest of 2018.

Learn more about the annual event and the camp at www.tropicalsmoothiecafe.com.

More smoothie deals are coming soon.

June 21 is National Smoothie Day and smoothie chains including Smoothie King, Planet Smoothie and Juice It Up! have specials planned.

Kelly Tyko is a consumer columnist and retail reporter for Treasure Coast Newspapers and TCPalm.com, part of the USA TODAY NETWORK. Read her Bargainista tips at TCPalm.com/Bargainista and follow her on Twitter @KellyTyko. Sign up for her weekly newsletter at www.tcpalm.com/featured-newsletter/bargainistabest