Whether you think a netbook is simply a small notebook or a compact machine kitted out solely for web access, rather a lot of buyers around the world are using them in place of their larger siblings.

In the Western economies and Japan, notebook shipments are declining while netbook sales are on the rise, market watcher DisplaySearch said today.

Take Europe, by far the biggest part of the Europe, Middle East and Africa (EMEA) conglomeration analysts like to treat as as a single market. In 2008, some 51.4m notebooks - laptops with screens 12in or more - shipped in EMEA, but only 7.3m netbooks did.

This year, DisplaySearch reckons, notebook shipments will have dropped 9.1 per cent to 46.7m units, while netbook shipments will have risen 80.6 per cent to 13.3m units.

The same pattern - notebook shipments down, netbook shipments up - can be seen in North America (down 1.1 per cent, up 136.9 per cent, respectively) - and Japan (down 13 per cent, up 29.1 per cent).

Overall, world notebooks shipments will decline a tenth of a percentage point year on year, DisplaySearch said, from 129.6m units to 129.5m. Netbook shipments will rise 99.1 per cent, from 16.4m in 2008 to 32.7m in 2009.

In China and Latin America, notebook shipments are still rising, but not by the same degree that netbook shipments are on the increase. And netbooks command a much higher percentage of the total shipments of mobile machines than they do in the more advanced economies.

It has to be said that notebook shipments far outweigh netbook shipments in EMEA, Japan and the US, so it's not like the notebook market is in terminal decline. But it's clear that netbooks are in demand. While price and portability are certainly key factors - a 10in netbook might not be much cheaper than a 15in notebook, but it's a darn sight easier to carry - there does appear to be a recognition on the part of consumers that they might not actually need the processing power that the bigger machines provide.

DisplaySearch said many netbooks are purchased as secondary laptops, but it's still telling that many buyers would rather have a second, ancillary machine than simply replace an old notebook with a new, more powerful one.

But there's another factor at play: reduced notebook consumption on the part of big business. DisplaySearch said it believes there is "significant pent-up demand" here, caused becuase enterprise held off upgrading from Windows XP to Vista but may well do so once Windows 7 shows up and the world economy picks up in 2010. ®