bottom line vs payback

bottom line

noun
  • The final balance; the amount of money or profit left after everything has been tallied. 

  • The summary or result; the most important information. 

  • A minimum acceptable result from a negotiation. 

payback

noun
  • A return on investment. 

  • An act of revenge. 

  • A benefit, reward, a form of recompense. 

  • A refund; reimbursement. 

How often have the words bottom line and payback occurred in a corpus of books? (source: Google Ngram Viewer )