How can I best measure the effect of on-line advertising?
Andrew GreenZenithOptimedia
BACKGROUND
The internet is very different from other, more traditional mass media like television or print. It is also a large and fast-growing medium worth around $18.5 billion worldwide in 2005.1
According to Nielsen NetRatings, the average surfer spends at least an hour every day on-line in the UK (representing 10–15% of all time spent using media), one-and-a-half hours in France and considerably more in the US.
From the point of view of marketers, the internet is different from other media in at least four key...