Marketing Sherpa is a great resource for tips, stats and case studies – if you haven’t checked them out before, I strongly recommend that you visit their website and also look at their newsletter subscriptions available.
Today I downloaded a great free report on email marketing. It is called “2008 Dirty Dozen Email Newsletter Mistakes”. The report covers a range of elements including opt in, frequency and segmentation and is worth a read, even if just for a refresh. You can access Marketing Sherpa’s free reports here.