It is common knowledge that Americans (especially women) spend a large portion of their earnings on shampoo. Despite the fact that a huge chunk of our budgets is devoted to this single product, we do not seem to consider whether the purchase is as necessary as we believe it to be. It is engrained in American culture that washing our hair every day or every other day is ideal. But -- is that really true? Do we really need to spend so much on shampoo? Is washing our hair frequently truly beneficial? The facts below will inform you of the real cost of your shampooing habits and will help you to decide whether or not your hair-washing habits should change. Here are the real facts about shampooing.

Americans wash their hair about twice as often as Italians and Spaniards.

According to shampoo-maker Proctor and Gamble, Americans wash their hair 4.9 times per week. This is about twice as often as people in other developed countries. We ask ourselves all the time why our hair is so prone to breakage, but it never really crossed our minds that maybe we are too clean. Are we too clean? The experts say yes.

Hairstylists and dermatologists say that we wash our hair too often.

Shampooing five times a week strips our hair of a beneficial oil known as sebum. Sebum makes our hair strong and healthy. When you strip your hair of this beneficial oil, your body compensates by producing even more oil and that's not good.

How often you wash your hair does depend on your hair type, to an extent.

Experts say that hair type is a good indicator of how often you should wash your hair. People with thicker and coarser hair generally do not need to wash their hair as often as those with very fine hair. People with oily hair will have to wash their hair more often. However, generally, it is best to wash your hair as little as possible. If your hair gets oily, dry shampoo is a great product to use. It helps to dry up the excess oil and keeps your hair soft and luscious.

Marketing campaigns may be tricking us into buying more shampoo than we need.

We see these marketing campaigns on TV all the time. There are always beautiful women with gorgeous-looking hair that bounces and blows in the wind, flawlessly. Celebrities such as Heidi Klum, Selena Gomez, and Sophia Vergara appear in commercials for shampoo to give the products star power. These beautiful women are very convincing -- but the truth is, these commercials are for marketing and the purpose of marketing is to make you want to buy a product. You may want to consider this before your next shampoo purchase.

Shampooing your hair less is eco-friendly.

If you are eco-conscious, this is definitely something to think about. Like all plastic items, shampoo bottles create a huge negative impact on our environment. To help our environment, environmentalists created the 'No Poo' Method. Although this method is not recommended to use for a long period of time since it can lead to dandruff, it still makes a point: We waste too many shampoo bottles because according to the experts, we shampoo our hair too often.

With that said, now you hopefully have a better understanding as to what the real cost of shampoo is. Based on my own personal experience, taking the advice of the experts improved the quality of my hair. I currently wash my hair two to three times a week and my hair was never healthier and more perfect than it is today. Even with the damage from color-treatment, shampooing less made my hair even better than before my hair was bleached. Many others are in agreement that shampooing less often improves the quality of their hair. You too can have better, stronger and more beautiful hair if you decide that the real cost of shampoo is not worth continuing your current hair-washing routine.