Data point: If you don't measure all the costs, you can't get a decent margin when you sell ROI

Pitney Bowes Launches Managed Address Services
from WhatTheyThink:
"On average, each piece of return mail costs the mailer $3.00 in operational expenses, according to Pitney Bowes research. That includes printing, postage, inbound handling, analysis, and re-mailing costs. It doesn’t include the cost of missed marketing opportunities, uncollected receivables and lost USPS discounts. In addition, unless the mailer pays for a special endorsement, undeliverable Standard Mail� is destroyed by the USPS."