I have been wondering for some time about dessert carts — the wheeled display cases waiters swing by your table after the main course has been cleared away, ostensibly to tempt you to order something you hadn’t wanted only moments ago.

Some restaurants use a dessert tray instead of a cart. Some foolish establishments even eschew fresh desserts and put out a “permanent” dessert display, a plasticized version that has more in common with taxidermy than pastry.

A fully loaded dessert cart pulling up to your table presents an overwhelming vista. On its decks are crowed plates and bowls bearing towering humps of cake and pie; barges of tiramisu; whip-cream-bedecked puddings, trifles, and cobblers.

If it’s early in the evening, the desserts tremble and glisten slightly, like the delicate brow of a debutante. If it’s late, they lean at odd angles, jiggle, and perspire heavily like an out-of-shape dad at a pick-up basketball game.

So here’s what always comes into my mind: Do these fulsome exhibits actually increase sales? As much as I love dessert — and I personally keep several bakeries open through my patronage — I’ve never ordered anything off a dessert cart.

Nor has anyone I’ve dined with over the years. Whenever the cart rolls up, my friends and I make a show of being impressed, oohing and ahhing — “Oh my, that looks rich!” —but frankly, we’re performing an old routine. The waiter knows it, too, as he leans on the dessert cart; there’s no hard feelings between us. “No thanks,” I say with false chagrin. “We’re having dessert at home.”

The point of a dessert cart, even a very elegant one, is to force the sale, to “[m]ake them have to say no,” in the pushy parlance of Chef2Chef.net, which bills itself as a “culinary portal” for professionals and cooking students.

This line of thinking seems to dominate the restaurant industry. Food Services of America, a restaurant supplier, advises, “[W]hen patrons actually see the dessert through the use of dessert carts and trays … your sales will improve dramatically.” Of course, Food Services of America sells dessert carts, so its opinion is not unbiased, but you get the basic idea: Show people a chocolate cake, and chances are they’ll buy a slice.

The National Restaurant Association makes a similar argument: Don’t just tell customers about your food and beverages; show them. For example, bring a dessert tray to the table so customers can see the decadent choices. It’s a lot harder to refuse “Chocolate-Raspberry Truffle Cake” once you’ve seen it up close.

This selling-by-showing approach makes sense in theory, but it doesn’t seem to work — at least not as it has been practiced until now. Dessert sales at restaurants have stagnated, and this may spell doom for the dessert cart as an institution.

Where carts once ferried shortcake everywhere from chic bistros to ballpark luxury suites, they may be eliminated as pastry chefs move more and more to smaller, bite-size desserts. It’d be ridiculous to portage bite-size desserts — cupcakes, shot glasses full of ice cream — on a soapbox-sized vehicle. It would make them seem heavy. And in this day and age, that simply won’t sell.

Already the dessert cart may be disappearing. Writing on Gothamist, New York City blogger Hugh Merwin said, “It may not seem to mean much, but the restaurant cart is a dying breed, even in fine dining restaurants where they once roamed freely through the perfumed air, the bespoke suits … Aside from the frenetic gridlock of Chinatown’s dim sum houses, almost no restaurants wheel fancy food around anymore.”

I can imagine a day when a dessert cart will be a true rarity, when I’ll point one out to my son in eager tones: “Look, Simon, here comes the dessert cart! They used to have these everywhere.”

Where will they go, these cast-away carts? To secondhand supply stores, no doubt, and auction houses. “Now bidding on Lot 5: Dessert carts,” the auctioneer will say with ill-feigned enthusiasm, casting a tired hand at a group of carts clumped together like deer with no place to hide. “Plenty good carts here. Do I hear $200?”

Someone, some traditional restaurateur who can’t give up on the old way, will buy them. Or perhaps some whippersnapper will buy them, a hipster with a notion to open Manhattan’s newest concept restaurant: Cart, where all your food has wheels.