Google’s Tim Reis calls mobile an “enormous branding opportunity” based on the amount of usage the platform is now seeing. As examples, he points out people play 570 years of "Angry Birds" daily; 600m year of YouTube mobile video played daily. 75% of YT Mobile user use mobile as their primary access device. Yet mobile so far only attracts 1% of marketing budgets, he notes, suggesting a dramatic gap in usage and advertisng. No wonder there’s 80% unsold inventory in mobile.