Amazon Prime customers grow by 3m in one week at peak of Christmas season

The three million included paying sign-ups and free trials.

A prime subscription includes two-day shipping, same-day delivery, superfast free two-hour delivery via prime now in more 20 cities (Sean Gallup/Getty Images)

The number of Amazon Prime customers grew by three million in the third week of December alone as shoppers looked to save on shipping holiday purchases.

A Prime subscription costs $99 (£79) a year and includes two-day shipping, same-day delivery, superfast free two-hour delivery via prime in more 20 cities.

The added members saw the number of items shipped for as part of Prime swell to more than 200 million.

“This was another great holiday season to be a Prime member, and we welcomed three million new members in the third week of December alone,” said Jeff Bezos, Founder and CEO of Amazon.com.

“Over 200 million more items shipped for free with Prime this holiday.“

The three million included paying sign-ups and free trials.

Amazon does not release the total number of Prime members, but it put the total number at ”tens of millions worldwide“.

Amazon including a range of facts in its press release announcing the record numbers. Among them, the company said the last order that shipped before Christmas was in San Antonio, Texas, at 11.59pm on Christmas Eve. It included Blue Buffalo dog treats, an Amazon.com Gift Card, the all-new Fire tablet, fruitables dog treats, LEGO Star Wars Death Star Final Duel Building Kit, Moleskine Classic Notebook and Stove Top Stuffing Mix.

New Prime customers will have to quit Prime before the end of January to avoid incurring the $99 (£79) a year membership fee that kicks in at the end of the free trial.

Even if those customers end up paying, Prime is still a better deal for the customer than it is for Amazon.

The company's account filings show that Amazon makes a loss on free shipping - and that this loss is getting worse over time.

Prime customers are important because they show Amazon shareholders that the company will make future sales.