The reason this isn't mentioned is that often referral programs are designed to be abused, so that metrics can be gamed just before an important funding round, a IPO, etc.
> often [referral] programs are designed to be abused
Heh.
As it happens my OH and I were sitting at the local playground this afternoon chewing the workplace cud - while vaguely watching our daughter play - and were discussing how often higher management types actually know what's going on at the coal face.
Past 5++ years were the golden age of VC subsidized rides, meal and grocery delivery. I never abused, but have downloaded an app, did one ride and totally forgot about the app.
Seen it happen many times.