Is Apple Inc. (AAPL)’s Falling Tablet Market Share Cause for Concern?

It looks like iPad hegemony is on the decline. Market researcher IDC has just released its preliminary estimates on tablet shipments in the fourth quarter, and Apple Inc. (NASDAQ:AAPL) is giving up some ground in terms of market share as competition escalates.

The iPad maker’s share of the booming market is now just 43.6%, a sequential decline from the 50.4% share it grabbed in the third quarter. Google Inc (NASDAQ:GOOG) Android is gaining ground, but not all of those unit shipments are benefiting the search giant directly, since Amazon.com, Inc. (NASDAQ:AMZN) ranked No. 3. Barnes & Noble, Inc. (NYSE:BKS) has now cracked the top five with its Nook tablet, which also runs a heavily modified, or forked, version of Android.

Source: IDC. Figures may not sum due to rounding.

A year ago, Apple Inc. (NASDAQ:AAPL) had a market share of 51.7%, so in percentage terms that’s a big drop. However, remember that the broader tablet market is exploding, and soared by 75% in units to 52.5 million. Since tablet adoption is on the rise, a drop in market share can still come with a big jump in iPad units sold. Apple Inc. (NASDAQ:AAPL) shipped 22.9 million units in the quarter, a 48% increase from a year ago.

Make room for Sammy
Much like how Samsung has made progress in the smartphone market, it’s doing the same in the tablet market. Some of the South Korean company’s gains come from Microsoft Corporation (NASDAQ:MSFT) Windows 8 tablets along with its usual fare of Android gadgets. Samsung saw total unit shipments skyrocket from 2.2 million in Q4 2011 to 7.9 million in Q4 2012, enough to grab it 15.1% of the market.

The new Kindle Fire HDs were also bound to be a big hit, following in the success of the first-generation model. Amazon’s Android tablet saw 6 million units move during the holidays, which is more information than you’ll get from the company itself other than its claim about it being the “#1 best-selling, most gifted, and most wished for product.” Investors want actual unit figures, Bezos, and they’ll get them one way or another.

Good news and bad news
Asus has also become a major player, thanks to its partnership with Google making the Nexus 7. The 3.1 million units that it shipped ranked Asus the No. 4 vendor with a 5.8% market share. Perhaps more importantly, if you cross-reference that total with CFO David Chang’s statements in November that the company is now building approximately 1 million Nexus 7 units per month after ramping up production, that suggests that the Nexus 7 comprised the vast majority of Asus’ tablet units during the fourth quarter.