"We have a challenge in filling the stadiums," Danny Jordaan, chief executive of the South African organising committee, told a press conference in Johannesburg.
"We have to educate our people to start buying their tickets for the World Cup when they go on sale next month," he said.
Soccer games rarely sell out in Africa, making it relatively easy for fans to buy tickets at the gate.
But doing so during the World Cup, which begins on June 11, 2010, will see many South Africans shut out and deal a blow to hopes that the tournament would have a heavy African influence in the stands. It is the first time the World Cup will be held in Africa.
FIFA President Sepp Blatter said the global financial crisis would not have a significant impact on the World Cup, though he added that the tournament might not be as profitable as the 2006 championship in Germany.
"The budgets have been composed, given and ratified. Naturally, we might not have the same return of investment as we had at the last World Cup in 2006, but the world was a different place then," Blatter told www.fifa.com
South Africa has vowed to finish building all 10 stadiums for the World Cup on time although the cost will be more than initially forecast, due partly to a weaker rand currency and higher construction costs.
Rising prices for imported cement, steel and other key building materials and higher labour costs have wreaked havoc on the stadium construction budget, leading to a 3.2 billion rand ($316 million) shortfall.
Local organisers are concerned about keeping the budget from spiralling out of control and finding the funds to meet the shortfall, which the South African government has already pledged 1.4 billion rand towards.
South Africa expects 450,000 visitors for the World Cup and hopes the finals will spur tourism and investment in Africa's richest economy.
