Although analysts have sometimes questioned the costs associated with Amazon Prime--the e-tailer’s program that lets customers receive free two-day shipping for a $79 annual fee-- the company has maintained that Prime encourages customers to buy more items and today it announced that it ships more items through Prime than its free shipping offer that lets customers receive free shipping on orders over $25.

Amazon has encouraged customers to use Prime by offering a number of benefits, including the Kindle Owners’ Lending Library where the number of e-books available to be loaned to members has increased from about 5,000 when KOLL launched last fall to over 180,000 today. Another benefit, the Prime Instant Vide, now has over 22,000 movies and TV episodes that members can stream."Amazon Prime is the best bargain in the history of shopping and it's going to keep getting better," declared Amazon chairman Jeff Bezos.

Among the factoids released by Amazon about Prime are: the top two items purchased with Prime this year are the Kindle Fire and the $79 Kindle. Kindle Touch is number three and the first volume in the Fifty Shades of Grey trilogy is number four; Prime now features more than 15 million unique items; the most borrowed title in the history of Kindle Owners’ Lending Library is The Hunger Games.