It Doesn't Take Much For Us - Does It?

Would someone please help me understand how adding the word "certified" in front of the word "used" or in front of the even more fancier term "pre-owned" car  lends more credibility to it? Doesn't the fact that the car was "used" or was "pre-owned" automatically certify it as used? (I have a B.A. in marketing, I get the gimmick piece of it).  But seriously are we that gullible? Do we not think we can get a "lemon" because it was "certified?" The same holds true for "As Seen On TV."  Does the fact that the product was seen on TV make it that much more credible? I know this is useless chatter, but it is something to humorously think about (LOL). That's the fun of a Blog. One can be as serious or as silly as one chooses to be at any given moment.