Push vs. pull economy

In the Frontline documentary on Walmart, the retail revolution is characterized as the domination of the “pull economy” over the “push economy.” What does this mean? What are its implications?
http://www.pbs.org/wgbh/frontline/film/showswalmart/

Technology company: In the documentary, Walmart is described not only as a dominant and innovative retailer but as a “technology” company. What does this mean? In what sense is Walmart a technology company?

Marketing strategy: Walmart’s “marketing strategy” is described in different segments of the documentary. Identify and describe various components of Walmart’s marketing strategy.

China Strategy: What is Walmart’s China strategy? Why did Walmart turn to importing from China a huge amounts goods it sells? How did Walmart go about implementing this import strategy? What are the consequences of this strategy?