The holiday season is still a few months down the line, but smart merchants know that planning their promotions ahead of time makes everything go more smoothly. Moreover, when you have all the time you need to strategize, you have the ability to create a truly differentiated customer experience.

After all, the holidays are always a whirlwind for retailers and shoppers alike. The former try to grab as much of the latter’s attention as they can, but usually in a time- and cost-effective way. These constraints—plus....