Amazon Kindle Fire may not be as popular as Apple's iPad. However, many analysts expected it to set ablaze the online retailer's quarterly earnings on Tuesday. The tablet did not disappoint.

Despite reporting a fourth quarter net income of $177 million, down from $416 million a year earlier, Amazon said revenue saw a 35 percent spike - it was up at $17.43 billion.

Prior to the earnings announcement, Stifel Nicolaus analyst Jordan Rohan said Kindle Fire has a stranglehold over the low-end tablet market. Rohan has upwardly revised Kindle Fire's estimated first quarter shipment from 5 million to 6 million and said "Amazon's device proliferation strategy" will reflect in long term revenues and margins.

"We believe that software attach rates correlate inversely with the hardware price. From Amazon's perspective, this could drive real upside in its North American media segment revenues," Rohan said. "From a cost perspective, the shift to digital delivery of content could help Amazon avoid costly free shipping subsidies. Hence, we believe there is a great deal more to the Kindle device strategy than most have discounted."

Jeffries analyst Youssef Squali is also of the opinion that Kindle Fire will boost Apple's topline. However, he has projected a lower figure for Kindle Fire sales.

Squali said he sees "potential upside from Kindle" but though Amazon may have shipped 5-6 million Kindle Fires, only 4 million may have been sold so far.

Amazon said, Tuesday, total Kindle unit sales (including Kindles and Kindle Fires) increased 177% in fourth quarter of 2011 compared to the same period a year earlier.

"We are grateful to the millions of customers who purchased the Kindle Fire and Kindle e-reader devices this holiday season, making Kindle our bestselling product across both the U.S. and Europe," Amazon CEO Jeff Bezos said in a statement.

"Kindle Fire is the #1 bestselling, most gifted, and most wished for product across the millions of items available on Amazon.com since its introduction 17 weeks ago," the company said.

Though Amazon didn't deliver killer results like Apple, yet, it cannot be denied that Kindle Fire is here to stay and despite facing threat from other cheap tablets, it will continue to dominate the low-end tablet market.