We want to be able to target snippets to users based on their count of unique domains visited in a subsession, after the session has been restored. We can use this to target people with wide/narrow ranges of browsing with different content (i.e. if someone is only going to 2 domains vs. someone going to 25, we may want to prompt different things - maybe test pilot or add-ons that are more valuable for highly-active users, etc.) Telemetry attribute >> browser.engagement.unique_domains_count (https://dxr.mozilla.org/mozilla-central/source/toolkit/components/telemetry/Scalars.yaml) Kate, please us know if you need anything else on this - hoping to get this with the 63 release.

I'm doing some Snippets 2018Q4 goals housekeeping, related to this bug. Could you update us on the status: Will this get implemented in 64? If not, should we expect it in 65?

This will not be in 64 and will not be in 65 unless re-prioritized