Reporter: Online surpassing TV in six months, do you buy it?

Paul Sweeney: Absolutely. I do. We're seeing the trajectory over the last really last 10, 12 years where we've got TV ad spending growing about 4% to 5% a year, but digital ad spending growing 15% to 20% a year, so that the lines are just about to cross here this year.

And I think if you look at the forecast over the next several years, coming from various forecasters, continued upward trend in internet ad spending, again, double digit growth versus television in the low single digits.

Reporter: So what does that mean for everyone else if Facebook and Google are getting the lion's share of the pie?

Paul Sweeney: Yeah, if I'm an advertiser or the ad agency's representing big advertisers, I'm worried, because I have a market where that really is a duopoly between Facebook and Google. I only have two buyers or two platforms to allocate my ad dollars. That is not a good market structure, market dynamic. And so what we're seeing is the incremental ad dollars that are going to the digital marketplace, again, Google and Facebook are taking just about everything.

So it's really a challenge for some of the smaller platforms. Think Twitter. Think Snapchat. Having 200, 300, 400 million users on your platform these days just is not enough. When you take a look at Google, you take a look at Facebook, each of Facebook's platforms is at or above 1 billion users, when you think about Facebook and Instagram and message. So it's just a tremendous reach vehicle.

And what we're seeing is the these big platforms, like Google and Facebook, are really starting to target television advertisers, because that's where the money is.

Reporter: Now something else that Meeker called out is that the measurement of the impact of online ads is still very much lacking. Also the placement of ads is sometimes rather suspect. Perhaps they might pop up next to offensive content. What do you make of some of these potential headwinds?

Paul Sweeney: These are significant risk and they're highlighted by not only advertisers, but the ad agencies that represent them. Measurement and context and placement are really the two big issues that these internet companies really have to figure out. That being said, the dollars are still going to digital. So you know, what's interesting, we're going to have a big data point coming out of the television industry over the next couple of weeks when they sell about 75% to 80% of their inventory in what's called the upfront market.

And you know, $19 or $20 billion will be allocated to television. The expectation is that TV ad spending in the upfront will be flat to down. And again, let's think about what's happening at Facebook and Google. They are seeing their revenue, their top online advertising revenue growth 20% plus. So you just have to compare those two markets. And you can see where advertisers are going, despite some of their concerns.