On the off chance you don't know what retargeting is, it is an increasingly common practice of creating banner ads that "follow you" from page to page after visiting your site. It is also a means to continually target potential customers who didn't open your e-mail.
Given that consumers are very well trained to ignore banner ads and e-mails hitting them with multiple messages isn't a bad idea on face value. BUT there is an art to it.
Your goal is to get the right message to the customer at THE RIGHT TIME. The right time does not mean ALL THE TIME therefore sometime it will eventually be correct.
If you know more purchase happen between 7:00 pm and 10:00 pm that might be an ideal time to retarget. Don't show me the same banner ad all day long, it's annoying!
When it comes to e-mail retargeting there is a right and wrong way to go about it. Do send the same content with a different subject and re-worked to appear different. DO NOT EVER resend the exact same e-mail and indicate in the subject line I'm being retargeted (yes this actually happened to me today.)
Lesson of the day: Think about the message you're sending from the perspective of your customer.
After years of seeing awful local marketing on cable TV, on the streets, and online I've decided it's time to do something about it.