Dealing from experience there has always been a greater open rate and click rate on emails that have some form of coupon. Working with one client of ours, they wanted to include a coupon in a newsletter email blast. The coupon was readily available on they’re website. We decided to put the coupon in the email to test the conversion rate. Wow! What a difference. They’re client clicks on the coupon was astronomical in comparison to they’re previous emails and to the click rate of the coupon on the website, ten times higher. Try adding a coupon to your next email blast to test conversion.