As Smartphones continue their phenominal growth, competition for ad space on these devices will surely shift dollars away from traditional TV advertising.  In an article by  Razorfish's Paul Gelb,  he explains that there are over 3 times the number of mobile phone subscribers than TV subscribers.  
As more folks use Facebook and other "free" apps on their smartphones, there are definate opportunities to present ads to consumers.  You Tube has been doing this for some time.  When you find a hot music video to watch, a short ad is placed at the beginning.  Consumers are willing to watch these ads for the "free" content they receive later...