A lot of my clients use different email system to handle their marketing campaigns. Whether it's RatePoint, Constant Contact, or some of their own proprietary platforms, they are all running into the same problem -- most modern email systems don't display inline images by default. This gives them the fear that their mailings are giving an even lower return rate to an already low rate. I tend to think that the people who pay attention to email-based advertisements are pretty likely to hit the "always display images from this sender" button, but you can never be sure.
