flack vs promo

flack

verb
  • To publicise, to promote. 

  • To hang loosely; flag. 

  • To beat by flapping. 

noun
  • A publicist, a publicity agent. 

promo

verb
  • To promote; to publicize. 

noun
  • an interview or monologue intended to promote a character or an upcoming match. 

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