ActivEngage’s good friend Jeff Kershner wrote a DealerRefresh post way back in 2008 called The ROI of an NADA Booth Model. Hilarious and creative, the blog is half mathematical formula for determining your “booth model conversion ratio” and half love note to a vAuto model named Andrea. We love Jeff’s style.

But with NADA right around the corner, it might be time for a fresh perspective. Split-testing data from recent trade shows has led me to take a position that I know you won’t all agree with: booth babes are losing you money.

I see fiery debate over this subject flare up now and again on the forums (especially when someone mentions the word Cardoll). It starts when someone launches into an impassioned argument against the exploitation of the female body to sell a product. Then others retaliate with a defense of the practice as an old-school enterprise that keeps the vendor offerings entertaining and effective.

I’m not coming from either of these angles. I’m talking purely about dollars and cents. Last week Spencer Chen, head of marketing and growth at camera app Frontback, published the results of an experiment he conducted back when he was on the product marketing team for a major public software company. The results insist that trade show models don’t convert.

Chen had a hunch that these booth babes were actually a drag on lead-gen, and here's how he tested his hypothesis: At several trade shows over a one-year period, Chen’s group reserved two booths on opposite sides of the showroom floor. The company staffed one of the booths with hot girls in skimpy outfits, and the other with older women (50+) recruited for people skills and dressed in business attire.

Astonishingly, the “grandmas” generated  3 times the amount of sales leads and conversions as the “babes.” What’s more, the “babes” attracted the kind of attendees that were far less valuable: cocky sales guys, nervous IT youngsters, guys who just wanted to get their pictures taken with a scantily-clad girl. I would attribute this huge performance gap to three possible causes:

1. Booth babes are intimidating.

A model at this year’s Consumer Electronics Show described conventioneers as “scared. They won’t even approach me.” True, she was probably talking about the desperate nerds on the Vegas floor, but it’s human nature to be a little anxious about approaching an attractive model. This inaccessibility can have the opposite intended effect at trade shows.

2. Booth babes don’t know your product.

When you staff your display booth with girls hired from a modeling agency, you aren’t hiring fully-equipped salespeople. Booth models don’t know how to demo your product or how look into the needs of prospective clients. Attendees on the expo floor know this; they’ll assume that you’re compensating for a bad product that couldn’t lure them in on merit alone.

3. Decision-makers don’t come to see the booth babes.

Dealer executives at NADA are there to improve their business, not to gawk at pretty ladies. They have an agenda to get things done. They know that their time there is a valuable opportunity for networking and education, and they aren't wasting it ogling. If you want to get a dealer’s interest, show him value, not cleavage.

Honestly, there could be a multitude of different reasons why Chen’s study turned out the way it did. Maybe it was the booth placement, or the type of trade show, or the time of day. But if you’re curious, this is the first quantifiable evidence that booth babes just don’t convert. For full coverage of NADA 2014, follow @activEngage on Twitter!