Two of the most important mineral resources of early West Africa was gold and salt.
Personally, I think it's because it was simple and free entertainment. Given that there wasn't a taboo around death and watching others die, and it actually being encouraged, like how it was in Anciient Rome, I'd say a lot of people would actually at least try out visiting a gladiatorial contest.
During active American involvement in World War II (1941–45), propaganda was used to increase support for the war and commitment to an Allied victory. Using a vast array of media, propagandists instigated hatred for the enemy and support for America's allies, urged greater public effort for war production and victory gardens, persuaded people to save some of their material so that more material could be used for the war effort, and sold war bonds. Patriotism became the central theme of advertising throughout the war, as large scale campaigns were launched to sell war bonds, promote efficiency in factories, reduce ugly rumors, and maintain civilian morale. The war consolidated the advertising industry's role in American society, deflecting earlier criticism.[1]
