Our /contactfilter allows you to create segmentation formulas (contact filters), and then use them to send campaigns to certain subsets of your contact lists. A filter can be applied to any contact metadata that you defined, like age, gender, and location. In addition, you can filter based on the opens and clicks (or lack thereof) by contacts for a specific period.
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Note: In order to use a contact filter, you must store additional data for your contacts. Please see here for detailed information. You also need to create a contact list, because the segmentation is applied to a contact list via the /campaigndraft resource.