To honor the 50th anniversary of the drink, McDonald's is making it available for purchase throughout the United States starting Wednesday. It's been three years since the shake was last sold nationally. In addition to the traditional green vanilla shake, McDonald's is selling a McFlurry version made with Oreo cookies. Both drinks will be sold for a limited time.
Temporary offerings like the Shamrock Shake help McDonald's create buzz and bring in nostalgic customers.
https://edition.cnn.com/2020/02/19/business/shamrock-shake/index.html