Market prognosticators have been hesitant to recommend Amazon, often concluding that the stock was overvalued. Perhaps this is not surprising considering a price to earnings ratio of 3569.50 over the last four quarters and the fact that the company was $274 million in the red last quarter.

Still the cloud side of the business keeps analysts guessing. After all Amazon Web Services, as the world’s largest utility computing vendor, is synonymous with cloud. And now the company is showing even more potential as it moves from startup enabler to enterprise solution provider with services such as Redshift, the new data warehousing product taking aim at HP, Oracle and IBM.

So is Amazon’s cloud business another low-margin activity like online bookselling or could margins be as high as, say, 50% – a figure that has been bandied about “off the record”? Amazon isn’t saying. The company does not provide a breakout of its cloud business earnings, but that does not stop analyst speculation.

Australian research firm Macquarie Capital estimates that as a stand-alone business, AWS would be worth $19-$30 billion or $41-$66 a share. The figure is based on a 5-8x multiple of Macquarie’s 2013 AWS revenue estimate of $3.8 billion. Macquarie further predicts that AWS will generate $6.2 billion in 2014 and $8.8 billion in 2015.

According to lead analyst Benjamin Schachter, the total cloud market is set to reach $71 billion in 2015 with AWS potentially capturing $38 billion, or 53 percent, of the addressable market.

Big data is thought to be a significant driver behind the bullish AWS forecasts, an opinion shared by Joyent CTO Jason Hoffman, who notes that many companies are opting to use the cloud, and by extension AWS, to handle their big data analysis. Hoffman is also part of the camp that believes Amazon’s upper cloud margins are in the neighborhood of 40-50%.

The Macquarie report is not the only predictor of Amazon prosperity. On Monday, Morgan Stanley analyst Scott Devitt improved his rating of the stock, setting a price estimate for Amazon of $325 a share. The same day, the stock reached a record share price, hitting a high of $269.30, and closing at $268.51.