When unidentified visitors enter a site that contains the Dynamic Yield script, they are given a unique Dynamic Yield identifier, called DYID. The DYID is stored in the cookies, session storage, and local storage of the browser. This enables us to track and target the user based on their behavior and metadata as long as they are using the same browser on the same device and do not delete the cookies and cache.
However, there are two additional levels of information about users you can provide Dynamic Yield which will enable richer targeting options and experiences.
Identified users
For Experience OS to target the same visitor across different channels (desktop, mobile, email) the visitor must be identified on each of the distinct platforms with the same Customer Unique Identifier (CUID). Users are identified when an event or API is sent to Experience OS with a CUID, but you can also identify site visitors that have been invited to your site in an email campaign.
Learn more about identifying users.
Matched users
Experience OS doesn't store any personally identifiable information (PII) about users. So, for example, when we receive an email address that identifies a particular user, we hash the email address before storing it to protect user privacy. This means that Experience OS can't use the email address or identify users externally without additional steps.
To enable triggered emails and audience export, identified users must be matched to an email address or other identifier. This is accomplished by creating a data feed of opted-in email users. The feed consists of one column of identifiers. Dynamic Yield then hashes these identifies and checks for matches among identified users. When a match is found, these users are called matched users, and are eligible to be included in triggered emails and audience exports. The unhashed email addresses are stored separately from our other data in a highly-secured location.
Learn more about email address feeds.