Sakaki is a very ambitious man and is intolerant of failure. Giovanni is shown to have access to vast wealth and resources. The money probably comes from Team Rocket's main source of income—the profit of selling stolen Pokémon. Giovanni also gains a lot of money from smuggling Pokémon, Pokéball trafficking, and other crime rackets. He has Team Rocket operations in both Kanto and Johto. He rarely meets people in person, as he prefers to communicate with his underlings via telecommunications.


(Source: Wikipedia)