Over the past six months, mobile RTB activity has grown significantly across our platform. Though the volumes in mobile are still smaller than “traditional” desktop RTB, mobile is expanding at a much faster rate.

That said, the future of mobile RTB is not without its challenges. One of the largest is that iOS traffic, which represents a large portion of the mobile web, remains cookie-less. Cookies are critical to desktop RTB because they enable buyers to identify unique machines and use data to make educated decisions about serving ads. Cookies are also important on the desktop because they make it easy for users to opt-out.

Though there are alternatives to cookies in mobile, such as using an encrypted version of the phone’s unique device identifier, these methods raise privacy concerns. In fact, for this and other reasons, Apple is expected to retire device IDs completely in their upcoming release of iOS. Other options, such as device fingerprinting, are interesting but today they also pose significant privacy questions.

While the industry works out a scalable and privacy-friendly solution to the lack of mobile cookies, Admeld has built its mobile RTB API to compensate and keep budgets flowing to our clients. With publisher consent, our bid request API can pass relevant opt-in data to buyers at the point of purchase so they can make a smart decision without a unique identifier. Types of opt-in data passed include age or gender supplied by the publisher, the user’s location, or information from the browser header such as OS, screen size, and carrier. 

We are also very excited about a few new data points that will be available to Admeld buyers soon. For mobile applications, we will be able to pass category, age restriction, and consumer "star" ratings in the bid request. The initial feedback we’ve been getting from buyers on this has been extremely positive.

In our view, the challenges of mobile RTB are few compared to its benefits. Many buyers are purchasing large quantities of ads through this method, and though it will never be the only way to buy, it will continue to break new ground in driving greater profits for publishers, better results for advertisers, and more relevant experiences for consumers.