The below response is from Mark Grether, Chief Operating Officer at Xaxis.
"The success we’ve seen with Facebook Exchange, Facebook’s RTB system, is going to have a major impact on the practice and economics of digital advertising in 2013. With FBX demonstrating the value of bringing RTB technologies into a previously closed digital ecosystem, we expect to see other major players begin to open up some of their inventory to RTB.
In particular, both Twitter and Apple (tablet/mobile) could conceivably launch their own RTB exchanges to take advantage of the benefits they see occurring to Facebook – and advertisers – through the launch of FBX.
For advertisers, the value of formerly unavailable, premium inventory becoming biddable via RTB is enormous. Just as with FBX, it will enable brands to better integrate their Twitter or Apple ad buys with the rest of their digital media spend. Advertisers will also be able to utilize their own first-party data and a wealth of third-party data to more finely tune their buys on these platforms. The result will be higher performing ads than these platforms would be able to deliver from a siloed model.
All of this premium inventory becoming accessible via RTB supports the growing centrality of audience buying to advertisers’ digital media strategies. At the same time, more available inventory doesn’t automatically translate into better campaign results if you don’t have the data and analytics tools to successfully access it. For the agencies that do, it should be a banner year for them and their clients."