* The show was canceled: Despite gaining a strong following, Family Guy was canceled by Fox in 2002 after three seasons.
* The show gained popularity in syndication: The show continued to air on other networks, leading to a growing fan base and a surge in popularity.
* DVD sales and merchandise: The show's popularity on DVD and through merchandise sales, like the "Peter Griffin" coffee mugs, helped convince Fox to revive the show.
* Renewed by Fox: The immense fan demand and the potential for profit prompted Fox to bring back Family Guy in 2005, resulting in the fourth season.
Essentially, the time between seasons 3 and 4 was a period of waiting and uncertainty for the show's future. However, the dedication of the fans and the show's continued success in syndication ultimately led to its revival and the release of many more seasons.