NEW YORK (TheStreet) -- Show me the profits! That was the message Amazon  (AMZN) investors on StockTwits had for CEO Jeff Bezos after the e-commerce giant announced first-quarter sales that topped Wall Street estimates, but also reported declining operating income, fueling doubts about Amazon's valuation.

$AMZN mrk cap 150 bln it means they must earn around 10 bln in future, could they do it? 10 with margin 4% they need to get 250 bln sales

-- kh (@khmusabaev) Apr. 24 at 05:38 PM

Amazon net sales grew 23% year-over-year to $19.74 billion in the first quarter. That beat analysts' calls for $19.42 billion, according to the Analyst Ratings Network. Earnings per share increased 5 cents from the same period last year to 23 cents, meeting analyst expectations. But, operating income declined 19% in the quarter from the same period a year ago to $146 million.

In the company's guidance, management told investors to expect worse operating income in the near future. Management guided for an operating income loss of between $455 million and $55 million. Net sales should fall between $18.1 billion and $19.8 billion, according to the press release. The mid-point of that number is just shy of the consensus estimate of $19.03 billion, according to stats on Yahoo! Finance.

Amazon's stock fell sharply from an initial pop in after-hours trading. Shares dropped more than 5% in the premarket. Amazon trades at more than 80 times expected 2015 earnings. Sentiment on the stock is divided, with 53% of the crowd calling for gains and the other 47% anticipating declines, according to StockTwits analytics.

Though Amazon reported strong sales growth, investors on StockTwits expressed fatigue with the 20-year-old company's startup mentality. They said Amazon should stop pouring money into new entertainment businesses that compete in Netflix's  (NFLX) and Apple's  (AAPL) backyards. Instead, the company should focus on expanding margins and becoming more efficient with its bread-and-butter e-commerce business.

$AMZN costs keep rising and margins keep shrinking.

-- David Trainer (@dtrainer_NewConstructs) Apr. 24 at 05:08 PM

See limited upside on a DCF eval. $AMZN needs >15% rev growth for 10+years, plus margins to increase to 5% from <0.5%. to support $350.

-- Chris Marc (@chris00nj) Apr. 24 at 08:38 PM

In the first three months of 2014, Amazon unveiled a set-top box, Fire TV, that will broadcast Netflix and other premium subscription services, as well as its own original series developed for subscribers to Amazon's Prime service. It raised the price of its Prime delivery service to $99-a-year -- some speculate to help offset the cost of investing in content. It launched "Prime Pantry," which offers basket foods, soft drinks and personal care items in bulk to Prime subscribers. Amazon also introduced its first offering for the video game market and struck an exclusive deal with Time Warner's (TWX) HBO to stream many of its hit shows.

$AMZN press release reads like a cable company. Maybe they shld get a cable co multiple. It would be a $6 stock then.

-- Rotten Al (@RottenAl) Apr. 24 at 05:31 PM

Of course, some investors say Amazon's ability to keep expanding into new territories is the reason to own this stock. After all, Kindle redefined how many people read books. Why shouldn't Amazon try to do the same thing for streaming videos?

$AMZN has been a revenue story from its entire existence. Perpetual dotcom status.

-- Michael James (@stubbybrown) Apr. 24 at 05:38 PM

$AMZN has PE of 500, people complain it's too high; while $AAPL has a PE of 12, and people complain it lacks innovation

-- zt (@taozhuo) Apr. 24 at 10:57 PM

Jeff Bezos shares that opinion that Amazon's innovation is the key to its success. "We get our energy from inventing on behalf of customers, and 2014 is off to a kinetic start," Bezos said in a press release. Long investors argue that, as long as Amazon can keep growing its top line upwards of 20%, investors shouldn't worry that its expected 2015 price-to-earnings multiple tops Facebook  (FB).

so many still obsessed w/ $amzn lack of margin. it's d ultimate GROWTH story. i'll worry abt margin when stops growing

-- Nic (@racernic) Apr. 24 at 04:45 PM

But the bears argue that's silly. Facebook is becoming a communication utility, as dominant as the cable company. Amazon, on the other hand, is competing with the cable company.

At the time of publication, the author held no positions in any of the stocks mentioned.

This article represents the opinion of a contributor and not necessarily that of TheStreet or its editorial staff.