In the readings of this week,we have learned about various types of social networks,auctions and portals.Based on your readings and additional research online, discuss with your peers the following three questions:

1. What do social networks, auctions, and portals have in common?
2. What are the four defining elements of a social network?
3. Why is Pinterest considered a social network, and how does it differ from Facebook?

This is an Global E-Commerce and Privacy Assurance Class