Fitbit as a work wellness initiative

So I've gotten involved with the Colby wellnes working group again.  The new guy in HR moved us in the direction of fitbits and shapeup challanges.  Which is fine.  The fasicinating element to the pedometer is the online or moble app.  The data collection and the end of week reporting is interesting in terms of "if you measure it you can change it."  Some of the measures they use are potentially just noise, bmi for example.  However the point is still valid.  I wonder how long the data logging will be interesting?