What is remarketing?

Remarketing and retargeting

The terms are used interchangeably, and where a distinction is drawn it is this: retargeting specifically means serving advertisements to prior visitors, while remarketing covers the broader practice of re-engaging known users across any channel — email, push, in-app, as well as paid.

The distinction is worth keeping because the channels have very different economics. Email and push are nearly free and reach only users who granted permission; paid remarketing costs money and reaches those who did not.

Where the value genuinely is

• Cart and checkout abandonment, where intent was demonstrated and something specific interrupted it.
• Lapsed customers with a history of value, who are cheaper to recover than to replace.
• Cross-sell to satisfied customers, which is the most reliably profitable form.
• Renewal and expiry, where the message is a service reminder as much as an advertisement.
• Not indiscriminate reach across everyone who ever visited, which is where most remarketing budget goes and most of it is wasted.

The measurement problem it shares

Every form of remarketing targets people already inclined toward you, so attributed performance systematically overstates causal contribution — the same structural bias as retargeting and re-engagement.

A cart abandonment email sent to someone who was going to return anyway records a conversion it did not cause. The rates look extraordinary, and the incremental effect is a fraction of them.

The remedy is the same everywhere: hold out a random share of the eligible population and compare totals.