buy into vs fall for

buy into

verb
  • To believe; to accept a craze or fad as valid. 

  • To buy stocks or shares of (a business). 

fall for

verb
  • To be fooled by; to walk into (a trap) or respond to (a scam or trick). 

  • To fall in love with. 

How often have the words buy into and fall for occurred in a corpus of books? (source: Google Ngram Viewer )