There is life after Harry Potter for (Nasdaq: AMZN).

The online retailer is off to a blazing start in 2008 with yesterday's lively first-quarter report. Net sales soared 37% higher to $4.13 billion, while earnings climbed 30% to $0.34 a share. Wall Street was a little short, expecting net income of $0.32 a share on $4.08 billion in net sales, but what else is new? The leading online retailer has now topped analyst estimates in six of the past seven quarters. (Check out Amazon's previous quarter here.)

Even if you factor out gains on healthier foreign exchange gains overseas -- a big factor when 49% of your sales are now stemming from outside of North America -- Amazon's top line still surged 31% higher.

The company still isn't giving out hard numbers on its new ventures like digital downloads or the fresh grocery experiment in Seattle. Amazon won't even reveal how many Kindles the company has sold, even though the supply problems for its multifaceted e-book reader appear to be licked now that the device is readily available.

Amazon prefers to speak in broad categorical terms. Its nonmedia sales are growing much faster than its flagship media business. Don't be surprised if Amazon begins eating into more traditional retailers like consumer electronics superstores and department stores. If Circuit City (NYSE: CC) and Best Buy (NYSE: BBY) are smarting, there's a good chance that it's Amazon gnawing away on market share.

Deceleration is relative
Is Amazon growing as fast as it was toward the latter half of last year? No, but we knew it wasn't sustainable. The company's own guidance indicated as such.

However, accelerating growth fans still can't be disappointed in eyeing the company's year-over-year steps over the past two years.

Sales Growth (YOY) 

Q1 2006


Q2 2006


Q3 2006


Q4 2006


Q1 2007


Q2 2007


Q3 2007


Q4 2007


Q1 2008


The balance of the year will continue to slow, but closer to the pace that Amazon was growing at a year ago than where it was two years ago. The e-tailer's guidance calls for net sales of $19.1 billion to $20.0 billion this year, or a healthy spurt of 29% to 35% in 2008.

Amazon Prime memberships, where online shopaholics pay $79 a year for free 2-day shipping and steeply discounted overnight deliveries on items sold directly through Amazon, are clearly helping. You won't hear it from Amazon itself, but when unearned revenue spikes by 76% over last year's showing, it's safe to say that the annual Prime memberships are tag-teaming with the company's booming developer Web services to drive growth there.

The digital divide
I can't wait for the day when Amazon opens up and tells us exactly how many digital movies, songs, and books it's selling through Unbox, MP3 Downloads, and Kindle, respectively.

Amazon has no problem declaring the breadth of its digitally available titles, like 115,000 Kindle e-books, but where are the visible numbers on the invisible products? This is where fat margins are waiting to be had. Yes, Apple (Nasdaq: AAPL) fans know that the content creators take a huge chunk of the revenue, but the merits of inventory-free stocking and the perpetual cheapening of bandwidth costs are too juicy to ignore.

Third-party data is already telling us that Amazon is moving a tenth of the music that Apple's iTunes is selling. Why don't we hear it from Amazon itself?

The lack of Kindle data is perhaps the most troubling, because this is where Amazon is riding on the hardware side, too. Owners and potential buyers are flying blind here. Is this a dud? Is this a hit? Is an updated Kindle on the way to clear up the original model's shortcomings? Is a price cut looming? It may be in Amazon's best interest to keep mum on those last two points until it's ready to take action, but I can't be the only one waiting on the sidelines to see the Kindle either evolve or earn its iPhone price tag.

In the end, Amazon's bottom line speaks louder than anything it doesn't say. Free cash flow over the past year is clocking in at a huge $0.8 billion. Remember when Amazon was piling on debt and selling stuff at lousy margins? Well, it's now growing and deliciously profitable.

Amazon's valuation may be rich, but there's no doubt that Amazon is here to stay long after the seventh and final installment of Scholastic's (Nasdaq: SCHL) Potter series has moved on.

Harry who?