I was at a client site that used Trilogy (an insurance company using their commissions engine.) One day, i'm told that Trilogy HR [unintentionally] implemented an exponential bonus scheme for referral hires. $1000 for one referral, $2000 for two, $4000 for three, and so on. The Trilogy consultants at our client site were laughing at the matter and joking about pooling together all the referrals so they could get $1000 * 2^10 in referral bonuses. Needless to say the bonus scheme was revised.