Email Marketing: The 50/50 A/B Split Test
Good article on how you should test your email list and how your list responds over a week period of time. Also, two free ebook downloads.
Email Marketing: The 50/50 A/B Split Test
"Email Marketing: The 50/50 A/B Split Test : Enterprise Email Marketing Solution : WhatCounts : WhatCounts will help you find and grow your email marketing ROI.Enterprise Email Marketing Solution…"
http://www.whatcounts.com/2012/06/email-marketing-the-5050-ab-split-test/
Email marketing to a select focused group rather than spamming to a mass of addresses with no interest in what you offer, is the safest and most profitable strategy.