Dynamic coupons are, of course, highly trackable and desirable. However, when customers cannot copy and paste their coupon codes from an email to the site, this creates a friction point. In particular, a mobile user may not have the ability to quickly jot down a 12-digit code and then accurately type it into a coupon code field on a mobile device. This friction point is easily one that turns a mobile impulse buyer into a, "I'll do this later at home" shopper who may not return. I would submit that making coupon codes copy/paste-able would not only improve the customer experience, but would likely increase conversions and therefore increase clients' perceived value of the platform.
Cathy Mace commented
I agree about adding a text option, but another issue I run into is that you can't do a transparent background with the images. We use the coupon code across multiple emails, sometimes in two different areas in the same email, and not having the transparent background option is causing a real headache as we move over from a different coupon manager. This should be something that we can do! Bare minimum, have text-based be an option!