Australians are being urged to holiday in South Australia over winter as the state launches a fourth round of its widely popular tourism vouchers, giving vacationers access to cheaper accommodation. Premier Steven Marshall announced on Monday the Great State Experience scheme will kick start a new round from late May after the 'magnificent' success of the program's earlier stages. About 50,000 vouchers will be up for grabs, offering either $100 off eligible CBD hotels or $50 off participating accommodation providers in regional and suburban areas for use over winter. 'We think it's really important - for June, July, August; months which are traditionally slower - to do everything we can to maintain and grow the number of people employed in this sector,' Mr Marshall told reporters on Monday.