The cost of 'free' shipping is not covered by the shipping fee.

The major carriers, including , and , handle numerous deliveries, and none of those packages are being shipped for free.

According to Kara Buntin, owner of A Cake To Remember on Etsy, people are drawn to free shipping because the word "free" is highly persuasive, even though they understand that someone else is covering the cost.

According to Pitney Bowes, parcel shipments worldwide are predicted to double in the next five years, potentially reaching 266 billion by 2026.

Ellen Reese, a sociology professor at UC Riverside and co-editor of "The Cost of Free Shipping: Amazon in the Global Economy," told CNBC that when consumers click the 'buy' button, they often do not realize the amount of labor that goes into delivering a package to their doorstep.

And those shipping costs are ever-increasing.

Dhruv Saxena, co-founder of ShipBob, stated that anyone can offer Amazon Prime two-day shipping, but it may incur a cost of $25 to $35 for a typical two-day shipping rate.

The U.S. Postal Service states that companies like Amazon, eBay, and even benefit from economies of scale because they generate mass online sales, allowing them to achieve bulk discount rates.

The Postal Service stated that it does not have any contracts with Amazon, Walmart, and Target for shipping packages, but there may be a negotiated agreement in place. However, the department cannot confirm or deny the existence of such an agreement.

The Postal Service stated that acknowledging the existence of a specific national service agreement would cause harm and is confidential commercial information that would not be disclosed under good business practice.

This story could not obtain comment from Amazon, FedEx, or UPS.

"Numerous small businesses have been struggling and shutting down due to intense competition, as stated by Jake Alimahomed-Wilson, a sociology professor at California State University Long Beach and co-editor of "The Cost of Free Shipping: Amazon in the Global Economy," to CNBC.

According to the Institute for Local Self-Reliance, three-quarters of independent retailers in a 2019 survey considered Amazon's dominance a significant threat to their survival.

It is challenging to predict the exact cost of shipping carriers and packages, which makes it difficult to offer free shipping without incurring a loss.

The video above reveals that free shipping is actually a myth, as it costs companies a significant amount to send parcels around the country, and can negatively impact consumer sentiment.