The best way to improve email marketing campaign results is to test and analyze campaign results for your specific audience. As an email marketing vendor, we analyzed the results of several thousand email campaigns to get a better perspective of what works, and what doesn’t work for business-to-business (“B2Bâ€) customers. We then distilled this down into a set of split tests to demonstrate a handful of interesting best-practices for email marketing. The split rest tips are summarized in this article in a Q and A format. Most of the results may also apply to business-to-consumer campaigns; however the results here are specifically form reviewing B2B email marketing campaigns. Q: I am running an email marketing split test. how many emails should I have for each email campaign variation in order to have meaningful data? A: If you are comparing the results for multiple email campaign variations, then you should shoot for the greater of the following: A test that will result in at least 100 data points per variation. For example if you typically see a 2% click rate and are comparing click rates in your email marketing results, then each variation should be sent to at least 100 / 2% = 5,000. If you have 4 variations, then you should send to at least 20,000 total contacts for meaningful results. Or, if you have a large list and are following best practices and varying only one item per variation, your total sample size should be 10% – 15% of the total contacts in the list. A: For basic split testing you should limit each variation to a single change. Otherwise, if you make multiple changes between variations, you will not be able to determine *which change* caused the different in response rates. On the other hand, if time is limited and perhaps you have created 2 or 3 different email campaign variations and want to see which performs best, then the versions can have multiple differences. Q: How do people respond to attachments – how do open rates with emails using attachments compare with emails not using attachments? A: Most spam systems will perform a virus scan on attachments, and many spam firewalls are set by default to
