The company expanded to 123 stores to sell the shoes, boots, and sandals, all with the negative-heel design, across the United States, Canada, and Europe.
[3][4][5][6] The shoes surged in popularity and were prominently featured on The Tonight Show Starring Johnny Carson and in Time magazine.
[citation needed] Soon, other firms, including Roots Canada, also marketed similar negative-heel shoes.
In 1977 Tarney Enterprises (Milwaukee, WI) negotiated for and received the exclusive rights to manufacture and distribute the shoes in North America.
[1] However, the distinguishing characteristic of the original Kalso Earth Shoes, the negative heel, is no longer available.