Growth & retention

Engaged subscriber

Definition

A subscriber who opened or clicked at least one email or SMS message within a defined recent window (commonly 90 days) — as opposed to a subscriber who is merely present on the list but functionally unreachable.

Defined in The Retention Audit: 12 Checks Before You Buy More Traffic.

Related terms

Owned channel: A communication channel where you hold the relationship directly, such as email and SMS lists built on explicit consent, as opposed to rented reach (ads) or mediated reach (assistant shortlists). No algorithm re-ranks who receives your message.
Zero-party data: Information a customer intentionally and proactively shares with you, such as preferences, intentions and context, as opposed to data observed from behaviour or bought from third parties. It is consent-clean and usually more accurate than inference.
Machine-visible trust: The part of your operational performance an AI system can check from data: review content and recency, delivery promises, published return and shipping policies, and support outcomes that become public. Agents can't feel your brand; they can read your record.
Trust transfer: The degree to which a shopper's confidence in the AI assistant that recommended a product carries over into confidence in the brand itself, surviving past the first purchase into repeat behavior. High trust transfer looks like an organic-search-level or better repeat rate; low trust transfer looks like a one-and-done customer who reverts to asking the assistant again next time.
Agent-influenced arrival: A new subscriber whose path to signup included an AI assistant's recommendation, comparison, or summary - on-site (a Brand Agent conversation) or off-site (ChatGPT, Claude, Perplexity, Gemini, Google AI Overviews, or Amazon's Alexa for Shopping). Distinct from organic browsing, where the shopper found and evaluated the brand unassisted.
Post-purchase Brand Agent: A Microsoft Brand Agent (in beta) scoped to post-order conversations — order status, delivery issues, warranty, product care, and returns — with access to live order data and the merchant's enriched catalog.

All 164 terms

What is AI invisibility costing you?

Revenue at risk from AI shopping channels, with the formula shown so you can check the maths.

Open the calculator Agentic Commerce Setup