Call of Duty: Advanced Warfare was supposed to fix the downward trend in sales for the COD franchise that began with COD: Ghosts. As of now it doesn't seem to be the case.
Cowen & Company did their analysis by comparing pre-order sales seen for the games in Amazon and this is what they concluded: "Advanced Warfare is now pacing almost 40 percent behind last year's Ghosts and almost 70 percent behind 2012's Black Ops 2. We continue to believe CoD will be down meaningfully vs. last year. With the franchise facing two consecutive significant year on year declines in sales, we think it is prudent to assume it has peaked."
In other words, the reign of COD is coming to an end. If you are thinking it is because gamers have stopped pre-ordering then you are wrong. In 2014 the record for most pre-orders for a game has been broken twice already, first by Watch Dogs and then by Destiny.
Long story short, the gamers have lost their interest on the franchise and no matter how much of a change Sledgehammer Games brought with COD: AW, it wasn't enough to drive sales. But maybe we are wrong and COD: AW will be used as a basis for better COD games in the future. Only time will tell.