First Project: achieve goals via social consistency

Hey all,

I'm a long time lurker, thinking of starting off with my first project, and need some thoughts on validating my idea and fine-tuning it.

I'm trying to build a platform where users can add goals they want to achieve and metrics to track such goals. The caveat being they assign 3-5 friends/family to track the goal for them, and only these assigned people can mark the goal/milestones as completed.

Example, I want to start running 5km within 5 months and have milestones of 1km -> 1st month
2km -> 2nd month
3km -> 3rd month
4km -> 4th month
5km -> 5th month

And assign my friends John, Doe, Rob as people to track this for me. The platform would then poll these people regularly. My friends in turn would ask me how I'm doing on my goal and then update the same on the platform.

This creates a social pressure to complete your goals.

Wdyt? Would you pay for something like this?