It's not hard to see the incentive for Amazon, of course. In order to enjoy the savings, you have to pour funds into Amazon -- and that means committing to a purchase at some point down the line. You may be tempted to load more money than you need just to be sure you'll have something on hand, and that reduces the temptation to buy goods elsewhere.

Even so, this could do a lot to expand Amazon's audience. The company recently launched its Cash service to court people without any bank cards, and Reload appears to be a logical extension: it addresses those people who have a debit card, but can't (or just won't) use a credit card. In some cases, it could mean the difference between buying online and having to pay through the nose at retail.