While TV ad spend took a fall during in 2008-2009 during the economic crisis, internet advertising spend continued on its upward path, offering advertisers more options when it comes to targeting the right consumers and tracking results of media campaigns and ads.
The quantifiable nature of internet advertising over TV advertising makes it appealing to advertisers - and offers a range of options from pay per click campaigns to cost per thousand page impressions. Online ads are also less costly to produce than TV ads - it’s not wonder advertisers are moving online.

Graph from Sfn.