Teaser campaign

A teaser campaign, also known as a pre-launch campaign, is an advertising campaign which typically consists of a series of small, cryptic, challenging advertisements that anticipate a larger, full-blown campaign for a product launch or otherwise important event; these advertisements are called "teasers" or "teaser ads". A teaser trailer is a form of teaser campaign.[1]

Teaser ad appearing a week before the release of the film The Idol Dancer (1920).