A product or advertising specialty given by a sales person to consumers to induce them to listen to a sales pitch.
Found on http://www.encyclo.co.uk/local/21023
a mechanism that automatically opens a door, as of a garage, when actuated by a radio transmitter, electric eye, or other device. · something that is effective in leading to opportunity or success: Sales experience can be a door opener for young executives. Found on https://www.infoplease.com/dictionary/door-opener