Are 98-loss Giants crazy to add depreciating asset in Evan Longoria?

Are 98-loss Giants crazy to add depreciating asset in Evan Longoria?  USA TODAY MLB Hot Stove: Rays trade Evan Longoria to the Giants for Span and three prospects  CBSSports.com San Francisco Giants' trade for Evan Longoria carries significant risk  Washington Post Jeff Passan on Twitter: "Source: Giants get Evan Longoria for Christian Arroyo, Denard Span, Matt Krook and Stephen ...  Twitter Giants Finally Make Splash by Acquiring Evan Longoria from Rays  Sports IllustratedFull coverage