 Within its first month on air , SpongeBob SquarePants overtook Pokémon 's position as the highest rated Saturday @-@ morning children 's series . It held an average national Nielsen rating of 4 @.@ 9 among children aged two through eleven , denoting 1 @.@ 9 million viewers . Two years later , the series had firmly established itself as Nickelodeon 's second highest rated children 's program , after Rugrats . It had gained a significant adult audience by that point – nearly 40 percent of the series ' 2 @.@ 2 million viewers were aged 18 to 34 . That year , 2001 , Nickelodeon took the " Saturday @-@ morning ratings crown " for the fourth straight season . In response to this weekend @-@ found success , the studio gave SpongeBob SquarePants time slots at 6 PM and 8 PM , Monday through Thursday , to increase exposure of the series . By the end of that year SpongeBob SquarePants boasted the highest ratings for any children 's series , not only on Nickelodeon , but on all of television . Weekly viewership of the series had reached around fifteen million , at least five million of which were adults . 
