To ascertain the importance of incentives, we need to begin with it's meaning and understanding what incentives are all about.
I like to subject incentives under the category of appreciation, a standard work behavior put in place and exercised as different working situations requires. Hence, Incentives can be any act of appreciation put in place to serve as inducement or motivation.
In a work place, incentives will mean inclusion on reward that motivates or compels effort. It might be in tangible form or otherwise. But in most cases, incentives are commonly exercised through the form of money, usually called bonuses. These bonuses as we know can motivate an employee's self willingness to work harder and produce better outputs.
If you look closely, you'd agree that incentives are more of a psychological workout. It's a pattern every human has become accustomed to right from the start of life. You play good, you get something good in return. The idea is already known to us and accepted by all. So I think it's best if every work place practice the act of appreciation as almost every single person can be implored in it's execution.