in a total of 7 seasons across more than one game, i have surpassed the expected sales total just once. i have always been down on previous seasons until my 3rd season at arsenal, and it seems more like a big signings than previous sucess boost sales (for top clubs anyway).
I took over a struggling CCC team in Blackburn in one game and sold quite a few but didn't sell out. My first season back in the Premiership, we sold out and have continued to do so ever since.