Quite simple email newsletter (because of technical restrictions of html emails) for a bedding manufacturer. Client reports some nice numbers (on past newsletters. this one is the latest one): click-through rate almost 40%, 10x traffic increase (the day email is sent) and most importantly more than 50x revenue hike compared to normal days – that means monthly revenue is up some 200% and about 2/3 of monthly revenue is generated the day the newsletter is sent out. I didn't believe the numbers until they sent me Google Analytics screenshots :-)