So Facebook’s founder Mark Zuckerberg has declared that “The next 100 years start today, and it’s going to be different.” Well both points are certainly true when isolated from the immediate context of his comments. But are they true for the audiences he is specifically addressing?

By saying that the next 100 years start today, young Mr Z. must surely be waving a derogatory digit at Google. From Google’s perspective, the next 100 years began in autumn 1997 when Backrub was renamed and made available to Stanford students. Mr. Z. thinks he’s onto something bigger and better than Google. And maybe he is. But the reality is that nobody can say for sure. Why? Well that’s because Google’s adrevenue model is proven and Facebook’s is not.

To date, Google’s adrevenue has been generated from a direct response model; PPC effectively took us back to the old results-based payment per inquiry (PI) deals. Direct response advertisers like paying for sales results and not for simply being seen. These direct response advertisers like the way Google’s performance based model works for them so the money flows straight in. For Facebook to take a share of this direct response revenue, it must deliver results that are at least as good as those generated by Google.

But Facebook has an ace and this could be where the $15bn comes in. Because of the way it is used, and because of the type of people who use it, advertisers may see it as more than a purveyor of direct response sales performance. They may come to view it as a place to talk about brands in targeted ways to highly targeted groups of consumers. This means that it could be liberated from the rigid ROI metrics that rule direct response. And that in turn means that advertisers may be prepared to pay more per person reached on Facebook and and be more relaxed about how it delivers ROI. From a media owner perspective, that’s a good place to be when it comes to counting the ad revenue dollars. In other words, the next 100 years did begin in 1997 for direct response advertisers, but they may just be about to begin again for brand advertisers.