On Tuesday, the online retailer warned that it may post an operating loss for the first quarter, as it spends heavily on new categories like tablets and on infrastructure for digital media and cloud computing services.

"While we had suspected Amazon's first-quarter margin guidance would underscore its ongoing investment spend, we were surprised by its lower-than-expected first-quarter revenue guide," Barclays Capital analyst Anthony DiClemente, who cut his price target on the stock 16 percent to $190, said in a note.

However, several analysts said the company's recent shift to more third-party sales and strong growth of digital media and services would continue to lift margins even as it slows revenue growth.

"Third party margins are considerably higher than those of direct (sales) as there are essentially no costs of goods and only limited fees overall for credit cards and bad debt," J.P. Morgan analyst Doug Anmuth noted.

Amazon gets about 5-15 percent commission on transactions done by other sellers on its website, as opposed to recognizing the full retail price as revenue on items it sells, according to Canaccord Genuity analyst Michael Graham.

The company had to rely more on third-party sales last year as the Thailand floods dented supply in such segments as disk drives, cameras and peripherals.

Amazon also said it saw a jump in sales of higher-margin digital content such as e-books, video, music and apps.

Of the 40 analysts covering the stock, 13 rate it a "strong buy," 12 a "buy," and 14 a "hold," with a mean price target of $233.90, according to Thomson Reuters's Starmine data. Only one analyst rates it a "strong sell."

Amazon shares have fallen more than 20 percent since hitting a record high in October, partly on concern about how much the company is investing.

They were down 10 percent at $174.94 in early trade on Wednesday on the Nasdaq.

"We think we could see some further weakness in Amazon shares in the very near term, but we'd view further pull-backs as buying opportunities," analyst Anmuth, who maintained his 'overweight' rating on the stock, said.

• A Permanent Economic Emergency