How has purchasing been influenced by new media?

[bigfather456]

For a university project I need to analyze the impact of new media on the purchasing process within major companies. I am having some trouble finding information about that, especially on how purchasing was handled before Internet/Email etc.
I also need to find information about the use of social networking for purchasing (not for marketing).
I appreciate everything you can tell me, or any sources you can name where I can find information.
Thank you!

[Justin Walsh]

If you are looking for general information on social media and how business is changing because of it I would check out Todaypulse's socail media guides. http://todaypulse.com/social-media-guide