Moss has been called selfish, has been accused of quitting on his team, displayed a sullen attitude and can be very moody. In addition, after a poor year in 2010, Moss sat out all of the 2011 season.
However, after working out Moss personally, 49ers head coach Jim Harbaugh and GM Trent Baalke made the move to sign him.
This is a calculated risk without a lot of downside. If Moss does not perform or if he becomes a distraction, the 49ers can just cut him loose, much like they did last year with Braylon Edwards.
The upside with Moss is very high, as the 49ers needed to improve their receiving corps following the 2011 season. Moss has 954 career receptions for 14,858 yards and 153 touchdowns. He is a future Hall of Fame inductee.
If Moss has anything left at the age of 35, he will be a welcome addition. He still has excellent speed and can stretch the field. His mere presence will open up the short-to-medium range routes for Michael Crabtree, Mario Manningham and tight end Vernon Davis.
Let's take a look at five key reasons why Harbaugh will get the most out of Moss.