For our clients using Motrain, we suggest using 1 point = $0.01 so the math is easier.
We suggest things like a course completion (ie. 10 min) is valued at 100 or 150 points (ie. $1 or $1.50), and friend referrals at 200 points. Then in the future, they can change that amount depending on how they want to influence behaviors.
For example, if they want to promote a particular course completion or referrals for seasonal low points, they can double these point values and address that during their marketing campaigns.