PC-Pro
Having already overtaken print advertising in terms of share of the overall ad spend market, online advertising has now eclipsed TV for years seen as an advertising monolith that could survive war and recession.
So why has TV advertising fallen behind online advertising?
Much of it comes down to measurement. Online advertising can be measured more accurately and TV ads, the latter measured by monitoring the viewing habits of a small number of 'Nielsen' homes to estimate the viewing habits of the entire country.
Online also carries less risk for the advertiser. If you advertise in the prime ad space half way through Corrie, or at half time in the World Cup Final, you'll pay top dollar regardless of whether 20 million watch, or just 20. You pay for the slot, not for the guaranteed eyeballs.
Online advertising can offer an alternative - you only pay for the ads that people actually see. If you advertise on a site that has a bad day, and thus doesn't serve many ads, you are not on the hook for a fortune in ad charges.
It's as simple as that.