Share American Idol closed out its eighth season last night with an impressive total audience of 28.84 million for the two hour finale. On average the show had an audience of 24.33 million this season. dtsv.dtse_post_741_permalink = ‘http://betweenthescreens.com/2009/05/idol-following/’; dtsv.dtse_post_741_title = ‘Idol Following’;