Google IO brushed on this topic and quantised the marketing potential of different forms of broadcasting in a graph: http://i.imgur.com/akG0F.png http://i.imgu

Google IO brushed on this topic and quantised the marketing potential of different forms of broadcasting in a graph: http://i.imgur.com/akG0F.png http://i.imgur.com/akG0F.png TV advertisers are restricted to one way flow of information, so advertising is about building brand. It's difficult to convert this into conversions. On-line advertising however have accurate statistics because of the available analytical software. Advertisers stick to conversions only as it's still a wild west when it comes to accurate impressions (even Facebook has been caught cheating on viewer counts). Until advertisers cater to surfers the full potential of on-line advertising won't be realised. I assume it's what caused the shortfall in Google IO's graph, I personally feel on-line marketing understated as a medium.