Rothenberg: Measured interactive advertising revenues are now at about $22 billion annually in the U.S. alone, and unmeasured spending -- for example, the amount companies spend on creating, running, and improving their own sites -- is probably even more. The bottom line, literally, is that this is a very large, very dynamic industry that influences every area of our economy. Although venture funding is as important here as in any other innovation-based sector, the interactive media industry is no longer the infant child of Sand Hill Road.

SmartBrief: Recent IAB stats suggest that search is thriving. How can online display adapt and compete with search in this changing environment?

Rothenberg: Display advertising is also growing, and until the recession was on an even steeper growth curve than search. While that curve has certainly flattened, the fact is that the major consumer-brand marketers that had been treating online media cautiously are shifting ever-larger shares of their budgets into interactive. That will continue, especially as online video continues to mature and prove its reach to and effectiveness with consumers. The overall display market also will grow, especially as media companies start building more marketing services, such as consumer insights analysis, around their advertising and media channels. But the biggest growth will come when the marketers, agencies and publishers can reach agreement on brand metrics that simplify the planning and buying of online advertising without sacrificing accuracy, acuity and actionability of the data itself.

SmartBrief: Will marketers still continue to invest in mobile and other emerging media amid the economic downturn?

Rothenberg: There are two widespread, clashing perceptions in the marketing and media marketplace right now. The first is that the recession will curtail R&D spending in the newer of new media, and that mobile will take a hit. The second is that 3G smartphones like the iPhone are game-changers, and are driving unheard-of amounts of traffic to mobile sites, their content and their ads. It's a fair guess that, even if overall investment flattens out, some very adept marketers, agencies, and publishers will use the recession to leapfrog their more risk-averse competitors and achieve leadership status in mobile.

SmartBrief: Will ad rates and the user base be able to underwrite high-quality video content online as has traditionally been the case on TV?

Rothenberg: Yes. A recent Bain & Co. study for the IAB indicated that premium online video ad inventory is selling out, and at very high rates. As consumers increasingly look at their laptops and desktop PCs as an advanced form of television -- you might think of it as "TV with benefits" -- the attractiveness of online video to advertisers will increase. Remember, until recently, major consumer segments such as packaged goods and automotive have lagged behind the cross-industry average in terms of marketing budgets allocated online. Now that they have discovered the branding benefits of online, video will be a growth segment.