 Following an 18 @-@ month development phase , Samsung unveiled the S III on 3 May 2012 . The device was released in 28 European and Middle Eastern countries on 29 May 2012 , before being progressively released in other major markets in June 2012 . Prior to release , 9 million pre @-@ orders were placed by more than 100 carriers globally . The S III was released by approximately 300 carriers in nearly 150 countries at the end of July 2012 . More than 20 million units of the S III were sold within the first 100 days of release . Samsung has since sold more than 50 million units . 
