Pertemps employs peer mentors to do that - former clients who through its training have got off the scrapheap.

BBC: Can private companies make the Youth Contract deliver?

Imagine, then, that you are charity with an interest in using peer mentors (old lags gone straight) to help ex-offenders, and you are considering bidding for one of the contracts.

BBC: A popular idea still on probation

But Y Combinator also supplied PlanGrid with mentors and peer pressure.

FORBES: How Silicon Valley Helped PlanGrid Lay its Foundation