Beyond the pure sales numbers -- tablets up, PCs flat or down -- there's a fair amount of anecdotal evidence that people are substituting tablet purchases for PCs. Adding to that, mobile ad network JiWire put out a Q4 report in which it surveyed more than 5,000 mobile consumers in the US and UK on a range of topics.
Among the findings in the report was the intention of existing tablet owners to by a second or additional tablets. The survey found that almost three-fourths of the respondents (existing tablet owners) intended to purchase another tablet.
It should be pointed out that the JiWire audience is not necessarily representative of the general mobile user population. It tends to be a slightly more "early adopter" profile. However I would imagine this finding is a kind of leading indicator of broader consumer sentiment.
HP's announcement of a $169 7-inch Android tablet earlier this week (putting more price pressure on the entire segment) argues that tablets will become an affordable and mainstream PC alternative for a broad consumer population, not just "affluents." Indeed, this result above suggest that many households will have two, three and even more tablets: one for each family member.
As I've argued before these devices (and smartphones) will be "primary," while the PC will be used for selected tasks and perhaps become a "secondary" Internet device in the home for large numbers of people. Developing markets may see even more dramatic patterns along these lines, with low-cost tablets simply taking the place of PCs in many instances.
An interesting, related finding in the JiWire report is the hierarchy of tablet preferences. The findings below reflect the international nature of JiWire's results. The Galaxy tablets have not done as well in the US but have done relatively well in Europe. In the US or North America, Kindle Fire has been the most successful Android device, followed by the Nexus 7.
What's particularly interesting is the position of Windows Surface machines in the third slot, above Kindle Fire. This indicates there's healthy awareness and interest in the device. However, we'll have to see in several months whether this translates into actual sales.