Keep your faucets and toilets and other plumbing from leaking and wasting water. Replacing old leaking parts will save you money every month on your water bill. Also when you upgrade to new fixtures in most cases they are much more efficient than the one being replaced. There are very few things we buy now a days that last as long as plumbing fixtures. They are definitely a better investment than an electronic good such as a smart phone or computer. How many times have you replaced those? Compare that to how many times you have replaced plumbing fixtures.