conversations.from: human
conversations.value: James pays $1000 for advertising.  It brought 100 customers to his site and 80% of those bought something at the store that cost $25.  How much profit does he gain from the ad?
conversations.from: assistant
conversations.value: 100*.8=80 customers bought something
  That means they were worth 80*25=$2000
  So he gained 2000-1000=$1000 from the ad