Done merely to get rid of a duty; performed mechanically and as a thing of rote; done in a careless and superficial manner; characterized by indifference; as, perfunctory admonitions
Alternatively it may mean that a perfunctory search is enough to ensure that a purchase is acceptable, so less search is carried out.
A perfunctory action is done quickly and carelessly, and shows a lack of interest in what you are doing. She gave the list only a perfunctory glance Our interest was purely perfunctory. + perfunctorily per·func·to·ri·ly Melina was perfunctorily introduced to the men. a perfunctory action is done quickly, and is only done because people expect it (perfunctorius, from perfunctus, past participle of perfungi )
hasty and without attention to detail; not thorough; "a casual (or cursory) inspection failed to reveal the house's structural flaws"; "a passing glance"; "perfunctory courtesy"