自从Canalys的报告发布后，人们对PC的概念更加困惑了。一方面是因为不同的研究人员对市场的定义不同，另一方面是因为PC和平板电脑的区别在迅速缩小。这种概念上的含混不清使我们难以估测各种各样的市场趋势。美银美林（Bank of America Merrill Lynch）今年1月发布的搜索引擎使用报告只有唯一的一个数据来源，那就是（传统）PC，因为无法获取移动设备搜索引擎的参照数据。如果不把移动设备的数据算进去，就算得出结论，宣称今年1月四大搜索引擎——谷歌（Google）、必应（Bing）、雅虎（Yahoo）和Ask——的搜索数量同比增长了9%，又有什么意义呢？“不幸的是，我们没有移动设备的搜索数据，无法反映搜索数量增长的全景。”美银在注解中解释。于是，这份报告附带地提到了一个事实：据一些搜索引擎广告商估计，移动设备的搜索数量约占搜索总量的15%。
Not surprisingly, the Canalys report got lots of attention and stirred much debate. Harry McCracken of Time magazine took the opportunity to poll his readers to find out what they thought. He added his own analysis and decided that a device is a PC if it meets the following criteria: It run apps; it is general-purpose (and not meant for singular uses, like a game console); it is meant to be used by one person at a time.
He then took a leap and said a PC can be "any size," meaning smartphones can count. But that assumption distorts the market for the simple reason that most people who own smartphones also own a PC or a tablet. Similarly, there are those who buy a tablet in addition to a PC, and others who buy them instead of a new PC. Granular analyses are needed to get a full handle on how and to what degree both tablets and phones are supplanting what most people think of as traditional PCs, and to what degree such devices are purchased as supplements to PCs. (Macs of course are included in the definition of PC, unless it's clear from context that they're being differentiated from machines running Windows.)
Since the Canalys report was issued, the confusion has only deepened both because researchers define the market differently and because the gulf between PCs and tablets is quickly narrowing. That confusion sometimes makes it hard to measure various market trends. A Bank of America Merrill Lynch report on search-engine use in January had to rely on numbers solely from (traditional) PCs because comparable data on mobile searches wasn't available. Is it even meaningful to note that searches on the four major search services -- Google (GOOG), Bing (MSFT), Yahoo (YHOO), and Ask -- rose by 9% in January from the previous year, when mobile data isn't included? "Unfortunately we do not have mobile query data to see the full picture for query growth," BofA's note read. So the report threw in the fact that some search advertisers estimated that mobile searches made up about 15% of the total.
The distinction between PCs and mobile devices remains important for analyzing other allied industries as well. The market for chips that run mobile devices is quite different from the market for chips that run PCs. A Morningstar report this month noted that chipmaker AMD's (AMD) recent troubles are in part due to the "headwinds" it faces thanks to "rapid tablet adoption." Meanwhile, Intel (INTC), which is dominant in desktop PCs, is coming under increasing pressure to show results in its mobile chip sales.
But when looking at the market as a whole, sans all these complicating factors, the trend is clear: Over the five years leading up to the release of the iPad two years ago, sales of traditional PCs and laptops grew anywhere between 5% and 15% a year, depending on the year and data source. Last year, sales declined about 5%, and a similar decline is forecast for next year. Over the 2012 holiday gift season, PC sales declined by between 6% and 10% over the previous year (again, depending on whose data you believe), even as the economy was recovering. Tablet sales leaped by between 60% and 80% during the season. Lots of people are buying tablets and forgoing traditional PCs.
That trend will continue. Over the coming months, more-powerful hybrid and convertible tablets will be coming on the market, and it seems clear that in just a few years time the differences between tablets and PCs will be negligible, at least from a consumer's point of view, though there will still be a market for traditional PCs for certain computing tasks.