<Table> <Tr> <Th> Time period </Th> <Th> Key developments at Amazon </Th> </Tr> <Tr> <Td> 1994--1998 </Td> <Td> <P> Amazon starts off as an online bookstore selling books, primarily competing with local booksellers and Barnes & Noble . It IPOs in 1997 . </P> </Td> </Tr> <Tr> <Td> 1998--2004 </Td> <Td> Amazon starts to expand its services beyond books . It also starts offering convenience services, such as Free Super Savers Shipping . </Td> </Tr> <Tr> <Td> 2005--2011 </Td> <Td> Amazon moves into the cloud computing area with Amazon AWS, as well as the crowdsourcing area with Amazon Mechanical Turk . By being an early player, it eventually dominates the cloud computing scene, allowing it to control much of the physical infrastructure of the Internet . Amazon also offers the Amazon Kindle for people to purchase their books as eBooks, and by 2010, more people buy ebooks than physical books off of Amazon . </Td> </Tr> <Tr> <Td> 2011--2015 </Td> <Td> Amazon starts offering streaming services like Amazon Music and Amazon Video . By 2015, its market capitalization surpasses that of Walmart . </Td> </Tr> </Table> <Tr> <Th> Time period </Th> <Th> Key developments at Amazon </Th> </Tr> <Tr> <Td> 1994--1998 </Td> <Td> <P> Amazon starts off as an online bookstore selling books, primarily competing with local booksellers and Barnes & Noble . It IPOs in 1997 . </P> </Td> </Tr> <P> Amazon starts off as an online bookstore selling books, primarily competing with local booksellers and Barnes & Noble . It IPOs in 1997 . </P>

When did amazon become the largest online retailer