#1.) Products already last a long time. If your product doesn't break during the original warranty period, chances are it will last beyond the extended warranty period too. Especially if you're not buying off-brand stuff.
#2.) Service plans are WAY too expensive. Most of them cost about the same as what you'd pay for one repair: Up to a third of the full cost of the product itself. Just save the money . . . and pay for repairs when you actually need them.
#3.) They rip you off in the fine print. Some plans start on the purchase date, which means they're covering the same period as the manufacturer warranty. Other times a company will give you a flimsy excuse and refuse to honor the contract.
--For instance, they could "determine" that the damage was YOUR fault. Or they could just say there's no authorized repair provider in your area.
#4.) Good companies will want to help you anyway. Companies want to keep their customers happy. Even after your warranty runs out, you might still get free repairs.
#5.) You might be covered by a credit card. Lots of credit cards offer benefits that extend a manufacturer's warranty for a year. So you might not need the service plan even if something DOES break.
#6.) State laws may already extend your warranty rights. Most states have laws requiring products to be free of major defects for a reasonable amount of time. So a court could force a company to fix something even after the warranty runs out.
#7.) It might be an easy fix anyway. If something breaks, a few minutes on Google might show you how to repair it on your own.
#8.) You can probably get renter's insurance cheaper. If you have homeowner's or renter's insurance, add whatever you buy to it. They might give better coverage for less money . . . and they don't run out.