This year, Amazon started heavily promoting free one-day delivery for Prime members.

According to the company, it attracted a record number of new Prime customers and trials this holiday season. Over 5 million people ended up signing up new Prime memberships or free trials in a single week during the holiday season. This was announced in a holiday recap Thursday. Fast shipping options likely helped spur that growth.

Hundreds of millions have been invested in Prim Free one-day and same day delivery by Amazon. Analysts are expecting Amazon’s free one-day shipping investments to pay off. When somebody subscribes to Prime, they tend to become loyal Amazon shoppers, even to the point where they are spending more a year than non-members.

RBC analyst Mark Mahaney estimated that free one-day shipping will spur Prime membership growth and Prime purchases overall, projecting an eventual annual revenue bump of $24 billion. According to a Piper Jaffray survey this month found that 55% of US Prime members said they will use Amazon more when numerous items are included within one-day shipping.

Amazon, who is typically light on specifics, said holiday orders with one- and same-day delivery almost quadrupled compared to the same period last year. One December 26, the company noted that over 100 million items sold by independent third-party sellers were shipped via Prime Free one-day deliver in the US during the holidays.

SourceGinny Marvin