Fiscal
The ease of pulling off a rudimentary DDoS attack means that the hackers aren't always the usual suspects. For example, a recent survey from Kaspersky Labs found that 48 percent of companies who had experienced a DDoS attack believed their competition was responsible. While these statistics may be slightly inflated due to human paranoia, at least some of the attacks being reported fall into the category of B2B cyber crime.
Along with causing productivity declines that reduce the efficiency of a key competitor, companies perpetrating these attacks also aim to damage the target's reputation. While there are no direct monetary gains for the perpetrator, the indirect benefit of not having yourself associated with a cyber attack is enough to draw customers away from the competition.