Glad you found the link useful. It's a fascinating subject!

Wow, fascinating stuff @sm2n!
Summed up in another quote from the same article: "For a tool that business depends so heavily on, we put little thought into how we use email." Very worrisome.

You reinforce some good points, Adam. The Pavlovian dogs theory about email addiction (an example of 'Classical conditioning') was nicely covered in this article, containing this succinct quote:
"Both slot machines and email follow something called a 'variable interval reinforcement schedule' " http://m.guardian.co.uk/technology/2008/aug/28/email.addiction?cat=technology&type=article