LONDON: The online audience in the UK will continue to grow over the next four years, but consumer behaviour will become more fragmented during this period, eMarketer, the online research firm, predicts.

According to the company's estimates, the UK's internet population will top 39 million people this year, and climb to 44 million netizens by 2013, equivalent to a penetration rate of 70%.

This increase even applies to children, with Ofcom having reported that two-thirds of five-to-seven year olds in the country will access this medium in 2009, as will three-quarters of five-to-seven year olds.

Moreover, the communications regulator has stated that over 70% of all web users now view material posted on the internet on a minimum of a daily basis.

By contrast, figures from the Office of National Statistics suggest that 64% of adults over the age of 65 years old have never done so, a total that falls to 5% for 25-44 year olds, and zero in the 16-24 year old demographic.

Further ONS data show that 40% of its panel had used their mobile phone, a handheld computer or laptop wireless connection to go online at least once in the three months to the end of August this year.

This activity was slightly more widespread among men than women, a trend which holds true, in slightly moderated form, for internet use as a whole.

"Marketers can be confident that virtually all segments of the UK population … are using the web more than ever to research products and services and to keep tabs on brand offerings," said Karin von Abrams, a senior analyst at eMarketer.

"But that has a downside for marketers, too. Audiences are fragmenting - mirroring the offline world … If your audience is not mass market, from now on you will probably need to work harder to keep up with them."

Data sourced from eMarketer; additional content by Warc staff