call bird

noun2

1. •
   A captive bird used by hunters to lure free-flying birds into a snare or trap.
2. •
   (figurative) Anything desirable used to lure somebody.

   • An example is the 'Kenwood Chef', a product which is so well known to the public that it is used as a 'call bird' by the discounters: the machine is given a conspicuous place in the shop [window] — 1983