Can ECID enable cross-site retargeting based on previous browsing behaviour?

[ab_cdef]

This might sound like a dumb question, but I’m asking anyway because it’s definitely out of my depth:

If a visitor lands on a website for the first time, they’re assigned an ECID. Let’s say they browse a few product pages and then leave without doing anything else (like creating an account or adding to cart). If they use the same browser to visit YouTube the next day, will the ECID still be retained? And can we start showing them ads based on the product pages they looked at on the website?

Thanks

[Harveer_SinghGi1]

Hi @ab_cdef,

ECID will be retained if the ID Service on both of these sites is using the same Org ID as the ECID returned by ID Service is based on the Demdex Cookie value and the Org ID sent with the ID request. If this is true, you should be able to personalize the YouTube content for users based upon their browsing history on the previous website.

However, if the ID Service is using different Org IDs on the website and YouTube then ECID will change and the user is treated as two separate users on these sites.

Here is the documentation that talks about how ECID is set:

https://experienceleague.adobe.com/en/docs/id-service/using/intro/id-request