free lunch vs giveaway

free lunch

noun
  • Something obtained without any payment, obligation or effort. 

giveaway

noun
  • Something that is given away or handed out for free. 

  • The act of giving something away for free. 

  • An indicator that makes something obvious or apparent. 

  • An event at which things are given away for free. 

adj
  • free of charge, at no cost. 

  • very low. 

How often have the words free lunch and giveaway occurred in a corpus of books? (source: Google Ngram Viewer )