Complex sentence: Earthlink eventually ended their sponsorship at the beginning of 2008, and the program went unsponsored for five months until the May 1 episode, when Best Buy became the sponsor of the program, featuring the same ad pattern as Earthlink.
Split into simpler sentences: Earthlink eventually ended their sponsorship at the beginning of 2008, and the program went unsponsored for five months. On May 1, Best Buy became the sponsor of the program, featuring a similar ad pattern as Earthlink.