These days a helpful clerk often reminds you that if the gadget you’re buying conks out after warranty you would be glad to have bought an extension. As with insurance, almost everything can be protected if you are willing to pay the price. But the proper question is: Is it worth it? And the answer is: It all depends.

Extended warranties used to be offered on only costly items like cars, television sets, refrigerators and washing machines. Now they can come with almost anything. The reason for the spread is that retailers like them as a new profit center. Consumer Reports says that in a time of squeezed profit margins, extended warranties can yield a 40 to 80 percent profit.

They can make sense for a laptop computer, which can be dropped, nudged off a table, or doused with coffee or a soda. For an automobile, it depends on the repair rate for a particular model and possibly on the quality of your service shop. Consumer Reports says its surveys show no unusually high repair rate for the new plasma and liquid crystal display TVs, but it notes that their long-term reliability is still untested. On cheaper small items, the best guess is probably to pass up the extended warranty.

If you do buy one of these extensions, balance the cost of the warranty against the likely cost of repair. Watch out for any warranty that starts the two- or three-year “extension” on the date of purchase rather than the date when the regular warranty expires. Some plans offer a repair rather than a replacement, and a repair may put your camera or electric shaver out of use for a long time. Finally, check your credit card to see if it offers a similar extended warranty on any purchase. Gold and platinum cards often do.

As with most decisions, think twice and read the fine print.