Osterman Research - Quantifying Costs and Benefits of Archiving Email and Other Content

http://i.zdnet.com/whitepapers/Quest_Quantifying_the_Costs_and_Benefits_of_Archiving_Your_Email_and_Other_Electronic_Conten.pdf
This white paper explains that the requirement to archive emails and other content may actually save you money. A good review on the topic of archiving (vs. backup).