When Jenny Goes to Amazon

When Jenny goes to Amazon.ca and buys The Da Vinci Code by Dan Browne,the website recommends other books by Browne.Jenny can even check to see what purchases she has made in the past at Amazon.ca.Amazon uses this sort of customer service to:

A) differentiate itself from other electronic retailers of books
B) prevent price comparisons with other electronic retailers of books
C) standardize its service offering
D) combat the problems associated with service intangibility
E) instil its importance to the customer