amazon-primeOne big advantage e-book readers have over printed books is the “instant gratification” they offer their users: as Amazon puts it, you can be reading any Kindle book within a minute of deciding you want it. And I’ve mentioned Amazon’s Disc+ program in which Amazon applies a similar principle to CDs and DVDs it sells.

But over the last six years, Amazon has been trying to do the same to its sales of, well, everything else. If they can’t deliver instant gratification, they can at least deliver it faster. This is the purpose of the Amazon Prime program, a shipping plan in which customers play $79 to get a year of no-additional-cost two-day shipping (or one-day shipping for an additional $3.99 per order) on every order. Business Week reports that the plan has proven so successful that other e-tailers are trying to copy it.

The article notes that members of the plan purchase more items from Amazon, and are more likely than non-Prime members to purchase things other than books and media from Amazon (which also sells goods in other categories such as groceries). It was more successful than even its creators imagined, breaking even in three months after its introduction rather than the expected two years. And as other companies are coming up with similar offers, including some free shipping overs during the holiday season, Amazon is moving toward offering next-day shipping instead of two-day.

It’s no surprise that the service would make people more inclined to shop at Amazon. Psychologically, if they’re paying almost $80 per year for shipping costs, they will want to “get their money’s worth” out of it by having as much stuff shipped as possible. And it will also inclined them toward purchasing from Amazon things they would otherwise have bought elsewhere—because, after all, they’re already paying for faster shipping from Amazon.

Of course, people who don’t want to pay for two-day gratification can still get free slower shipping from Amazon if they order over $25 worth of merchandise at a time, which leads some to suggest it is not such a bargain after all. In the end, it depends on how much value the individual customer assigns to getting the item he orders only a couple of days after he orders it.

Until we have Star Trek-style replicators and transporters, “instant” gratification for physical objects is going to be limited to people who purchase them in the store—or those who buy e-media, such as e-books or streaming movies. The success of the Prime plan suggests that a lot of people would pay to have their items faster—which suggests that impatience might be a helpful factor in the adoption of e-books over physical ones.