Africa revisited: Geographic size vs Economic size

[Islandman]

Please forgive me if i cannot get excited about how large Africa is compared to other countries or continents:

Three largest economies in Africa are:

GDP of South Africa $524 billion
Size of South Africa 471,400 sq miles

GDP of Egypt $497.88 billion
Size of Egypt 387,000 sq miles

GDP of Nigeria $377.9 billion
Size of Nigeria 356,669 sq miles

Compare to:

GDP of South Korea (2011) $1.12 Trillion
Size of South Korea 38,000 sq miles

GDP of Taiwan (2011) $466 billion
Size of Taiwan 13,972 sq miles

GDP of Singapore(2011) $240 billion
Size of Singapore 275 sq miles