From the Elsevier Reviewer's Packet:
"Elsevier shares the view of many that all scholars who wish to contribute to publications have an obligation to do a fair share of reviewing."

I don't disagree necessarily, but it seems a bit self-serving coming from one of the major publishers of toll-access journals--journals built by academics who seek to publish in them, academics who provide free labor in reviewing for them, and academic libraries who purchase them.