Amazon.com (AMZN) - Get Report was a little more reserved about what it chose to share about holiday season sales this year compared with last year. But it did give away some useful nuggets for investors. These include:

1. Alexa-based shopping grew significantly

Amazon says that -- without providing sales figures -- "use of Alexa for shopping more than tripled" this holiday season compared with last year's. The remarks come a year after the company stated "millions of Prime members" used Alexa for voice shopping.

The rapid growth seen in the installed base of Alexa-capable devices -- thanks to both Amazon's own hardware sales and the mushrooming of third-party devices that support Amazon's voice assistant -- clearly has a lot to do with Alexa's voice-shopping momentum. So does (judging by survey data) growing consumer awareness of, and comfort with, the concept of placing online orders by voice.

Voice shopping isn't ideal for all e-commerce uses -- in general, it works best when consumers know exactly what they want to buy and from whom. But there are certain items, such as consumer staples bought on a recurring basis, for which it can be more convenient than shopping through a website or app. And though Alphabet's (GOOGL) - Get Report Google Assistant will enable some of it as well, Amazon is pretty well-positioned to drive a lot of that activity in the U.S. and elsewhere.

2. 'Tens of Millions' Signed up for Prime

"Tens of millions" of people signed up for Prime free trials and paid memberships, says Amazon, which typically sees sign-ups for 30-day Prime trials spike during the holiday season. The company didn't make a similar comment last year, but it did say at the time that it recorded over four million new trials and paid memberships in a single week.

Amazon is eight months removed from announcing that its global Prime membership count has topped 100 million. In the third quarter, the company's subscription services revenue, which covers Prime membership fees as well as services such as Amazon Channels and Music Unlimited, grew 52% year over year to $3.7 billion.

3. The Average U.S. Prime Account Likely Ordered More Than a Dozen Items

Amazon says that over a billion items were shipped for free in the U.S. via Prime. The company hasn't broken out how many Prime accounts it has in the U.S. But the figure is possibly around 60 million, based on a Cowen estimate from January (citing a survey of 2,500 consumers). Another estimate, made by research firm CIRP in October, shows there are 97 million U.S. Prime members, but that figure appears to separately count multiple consumers relying on the same Prime account.

Assuming Cowen's estimate is close to the mark, Amazon likely shipped over a dozen items per U.S. Prime account this holiday season, and perhaps more than 15 items. The average U.S. Prime member spends $1,400 per year on Amazon, CIRP estimates, and data from e-commerce analytics firm Rakuten Intelligence indicates Amazon's e-commerce share spikes during the week before Christmas, because consumers trust it more than rivals to deliver orders on time.

4. An iPad Made Amazon's List of Top-Selling Electronic Devices

Amazon says that in addition to products such as Bose's QuietComfort 35 wireless headphones and a 65-inch, 4K, Samsung TV, the 32GB, space grey, Wi-Fi-only version of Apple's (AAPL) - Get Report standard iPad was among its best-selling electronics items this holiday season. The tablet, along with other Wi-Fi-only standard iPad models, has been discounted in recent weeks, 

The fact that Amazon gave an Apple device a shout-out in its post-Christmas PR (unlike in prior years) might just be a fresh sign of thawing ties between the companies. In November, it was learned that Amazon and Apple had

struck a deal

under which more Apple products will be directly sold by Amazon (rather than third-party sellers). And a little over a month later, Amazon's Echo speakers began supporting Apple Music content.

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