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In legacy Blueshift you may be sending events that include the retailer_customer_id or customer_id in the event payload so that event gets recorded to the correct profile. In legacy Blueshift the customer_id is made of a combination of the advantage customer number and email id.

The refactored instance of Blueshift will be email centric meaning the email address will be the main identifier for profile matching. The customer id will in the new instance is made up of the profile key which will be included by default as a URL parameter. This profile key (pk) is comprised of the affiliate id and email address which is MD5 hashed. The profile key can be passed back as the customer_id to tie an event back to a user profile with out needing to decode the vid2 value.

You can read more about the vid2 parameter here.

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