I used a buck decoy last season, end of October. Only stuck one antler on. Pulled in a 120" to 35 yds. and my wife hit got a good shot at him. Never found him because it got little penetration from a shoulder blade hit but I believe she never would've got close without the deke. Plus it puts the deer's focus on it and they get a little less wary on the way in. Lots of guys say they spook more deer than not, but I have had pretty good results so far.
my taxidermist used one this year and said he always will from now on. he shot a doe over his...he said as soon as she saw it she never looked at anything else even when she got shot...she ran a little and turned back to look at the decoy when she expired.
and on tv....well...we all know how they work on tv lol