Instead of gaming the rewards, make the game rewarding.
When it comes to CRM--"No single event has very much value."

Don't feed the distrust cycle

In all human beings, loss aversion can lead to enormous distrust. In other words, if someone has cheated you, you are likely to become distrustful of everyone. This behavior is not only irrational, it's incredibly damaging. Tq-120720-td

As co-workers, we must keep on trusting in order to work effectively. I recommend that if you are cheated, you share your grief. Don't bottle it up because it will make you too cautious. Blaming is also poor behavior, so focus on how bad it made you feel, and other people will be sympathetic. Use that emotional support to trust again.

NY Times: Why You Hate Work, 2014-May-30 by Tony Schwartz and Christine Porath

Partly, the challenge for employers is trust. For example, our study found that employees have a deep desire for flexibility about where and when they work — and far higher engagement when they have more choice. But many employers remain fearful that their employees won’t accomplish their work without constant oversight — a belief that ironically feeds the distrust of their employees, and diminishes their engagement.