Financial incentive works well in industries with uninspiring work or products. Unless private bankers, insurance agents, or janitors go to work to fulfill a higher mission, financial incentive works well for them.
But, it does the opposite in industries with inspiring work or products such as non-profit organization, or startup.
People who join a non-profit organization likely do so because they believe they are making a difference to the world despite the modest pay. If you introduce a bonus system to reward each donation secured, soon, the staff's motivation turns to the monetary reward. Securing a donation becomes more important than other non-incentivized equally important tasks in the organization.