Anything that can be measured can be improved upon. There are many ways you can test and refine email marketing campaigns to increase your earning potential.

Below are some of the most common tests that you can implement to improve your email marketing campaign effectiveness and that will help you build a better understanding of what works, and what doesn't.

• open rates
• conversion rates (buyers)
• subject lines (to see what converts better)
• compare email lengths S
  
• compare linking strategies (call to action, straight URL)
  
• bonus vs. non-bonus
• type of copy (conversational vs. essay)