Why is saying a product will last 100 + years not deceptive advertisement.?

Question

How does a company know there product will actually last 100 years or more; all the testing in the world couldnt go through every possible situation that may occur in the timespan of 100 years.

Lets say a person buys something that is said to last 100 years in 2008 and there still alive in 2108 and the product doesnt work. If they were able to find the company could they sue for deceptive advertisement.

Answer 1

Because a lie is only a lie if you can prove it.

Come back in a 100 years with the product that made the claim and we'll talk.