earn vs obtain

earn

verb
  • To achieve by being worthy of. 

  • To cause (someone) to receive payment or reward. 

  • To receive payment for work. 

  • To gain (success, reward, recognition) through applied effort or work. 

obtain

verb
  • To get hold of; to gain possession of, to procure; to acquire, in any way. 

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