So well, in fact, that the tablet market is often characterized as being a two-horse race between the tricked-out Amazon e-reader and Apple’s iPad.

But when it comes down to the numbers, the two companies couldn’t be more different, like comparing Apples to oranges.

Tomorrow, Amazon is expected to report a giant fourth quarter, but it’s guaranteed not to look anything like Apple’s monstrous results reported last week for the same period.

Here’s one data point: For the holiday period, Apple’s gross margin was an impressive 44.7 percent, up from 38.5 percent a year earlier. Meanwhile, analysts are estimating that Amazon’s operating margin will fall to 1.3 percent from 3.6 percent last year.

The specifications of the two tablets can be compared side by side, but a completely different vocabulary is needed to speak intelligently about the two businesses. Simply put, Apple is a hardware maker and Amazon is a retailer.

One has very high margins and the other doesn’t, resulting in two drastically different financial outcomes today. But over time, the idea is for that to change.

Rather than making money from hardware sales, Amazon’s approach to the Fire is to generate incremental sales from other goods and services on the device. Some analysts feel that, over time, that play can create a reliable and recurring revenue stream – and ultimately higher margins.

Tomorrow, Amazon is expected to report sales of $18.3 billion in the fourth quarter, up more than 40 percent from the same period in 2010, according to FactSet Research. Q4 earnings are expected to fall notably to 17 cents a share from 91 cents a year ago.

While revenue growth is impressive, the company’s profitability is being weighed down by losses from the $199 Kindle (which is not quite a break-even proposition), the construction of more warehouses across the globe (17 were added in 2011 for a total of 69) and other investments in infrastructure, like its cloud-computing services and media services, like video, music and e-books.

In contrast, Apple has a rich markup on its iDevices and doesn’t have much of the same overhead as Amazon.

Still, the number of consumers Amazon touches in just one quarter is staggering, and it continues to take share from brick and mortar retailers.

As J.P. Morgan analyst Douglas Anmuth points out in a report, e-commerce grew about 15 percent in Q4 in the U.S. due to strong holiday sales, but he expects Amazon’s growth rate to more than double that to 47 percent year over year.

Anmuth is also bullish that while the fourth quarter could represent a “low point for margins,” Amazon could start seeing an uptick in margin as soon as the first quarter, now that a number of services and some key infrastructure are set in place.

However, don’t expect much insight tomorrow into the company’s long-range plans. The Seattle-based company is typically short on details during its earnings release and call.

If it follows standard protocol, it could provide an update on warehouses being built next year, number of employees and other infrastructure investments, but will likely dodge answers about how many Kindles it shipped during the quarter, or how much Kindle Fire owners are purchasing on the devices.

For now, we’ll have to settle for analyst estimates.

On Sunday evening, Stifel Nicolaus analyst Jordan Rohan raised his estimate for fourth-quarter Fire sales to six million units from five million.

While only on the market for a limited time, that’s still a lot less than Apple, which sold 15.43 million iPads, up 111 percent year over year.

Amazon’s stock dropped 1.65 percent, or $3.22, today to close at $192.15 a share.

Extrabux, a price comparison site that pays you cash for making purchases from particular retailers, has compiled a list of the best and worst states for e-commerce customers.

The company said it evaluated four factors when making its list: Shipping time, including the location of many warehouses; shipping costs; sales tax rates; and states where you don’t have to pay sales tax at all.

The top five states were generally praised for having the lowest shipping costs, the fastest shipping times and the cheapest sales tax rates (if they charged at all).

1. Delaware
2. Mississippi
3. New Hampshire
4. West Virginia
5. Oregon

The five states at the bottom of the list ended up there because of long shipping times and high costs due to shipping or sales taxes or both. The results may surprise you, since the group includes two states with big populations and the state where Amazon.com is based, among other e-tailers.

1. Hawaii
2. Alaska
3. California
4. New York
5. Washington

A full breakdown of the reasons these states were chosen can be found on the Extrabux Blog.

Hoopes contends that global solar demand headwinds are unlikely to subside for at least the next few quarters. “Take-or-pay contracts are only as good as the counter-party’s willingness and ability to do either,” he notes. Hoopes points out that Q-Cells, on its Dec. 9 conference call, said it will allow a flexible delivery schedule for customers and will also offer discounted prices to help share the burden.”

Read the rest of this post