After last year's blockbuster Ad Trader Conference in Hamburg, we are going big this year with some of the most influential ad execs in the industry already confirmed to speak. This year's theme of the conference will focus on building sustainable relationships between the demand side and supply side in the evovling German data-driven ad marketplace. Germany remains the biggest display market in Europe, but it will not move in the same way as the UK and France in terms of how real-time media buying is adapted.

The sales houses are very strong in the German market, and most remain unconvinced of automated buying. However they realise change is on the horizon, and it is with this in mind that we are looking to bring together some of the biggest sales house players in the market - as well as senior figures from the demand side and the ad tech space - to discuss and analyse the potential of data-driven online advertising in Germany.

2011 was dominated by lots of industry chatter around the potential of automated buying and real-time trading. 2012 is about application and making this new eco-system work.

The Ad Trader Conference is the biggest independent conference on the data-driven display marketplace in Germany. ATC Hamburg will have over three hundred online senior advertising execs in attendance - and will attract some of the biggest buy side and demand side players in the market.

ExchangeWire will be chairing two panels at the event. The first will focus on the technology enbling and powering the current move to automated buying; and the other will explore the potential models that will work for German sales houses in the dynamic marketplace. Our editor, Ciaran O'Kane, is looking forward to hosting two of the biggest international names on the day - AppNexus' Brian O'Kelley and Brian Lesser, Xaxis CEO.

Brian O'Kelley is one of the most influential figures in ad tech - and is currently CEO of AppNexus, a key tech provider in the new real-time ecosystem. He was the former CTO at RightMedia, helping to launch the first ad exchange for online display. As CEO of Xaxis, Brian Lesser is arguably the most powerful man in the burgeoning data-driven ad marketplace. Xaxis is a global digital advertising company servicing over 700 marketers in 13 markets - effectively acting as the optimisation layer for the entire global GroupM operation.

Tickets are selling fast for Germany's premium event on the data-driven marketplace. Book your early bird tickets today. Details of speakers are available on the Ad Trader Conference site.

Brian O’Kelley, CEO, AppNexus

Widely considered a visionary in the field of online media, Brian created the first successful ad exchange as CTO of Right Media (acquired by Yahoo for $850MM in July 2007). Prior to Right Media, Brian was CEO of Netamorphosis, an early social networking and e-commerce site for events and venues. Brian was also an early innovator in real-time personalization and real-time ad optimisation at LogicSpan, a consulting and technology integration firm, and later co-founded Cetova, a web-based reporting and analytics platform for enterprise financial systems. While earning a computer science degree at Princeton University, O'Kelley started a web design firm, building an open-source e-commerce engine used by more than 100 companies. Brian is an active partner at Grape Arbor, an angel investor group. Since its founding in 2006, Grape Arbor LLC has made investments into more than a dozen technology companies.

Brian Lesser, Chief Executive Officer, Xaxis

Brian Lesser is Chief Executive Officer of Xaxis, a global digital advertising company servicing over 700 marketers in 13 markets. Brian is responsible for delivering targeted digital media products that allow advertisers to reach and better understand their audiences at massive scale. Xaxis delivers these products through the expert use of consumer data, advertising technology and media relationships.

Prior to his current role, Brian was Senior Vice President and General Manager of the Media Innovation Group (MIG), a company he founded in 2007. As the leader of the MIG, WPP’s first technology development organization dedicated to media buying and optimization, Brian created the first integrated data management, targeting and ad delivery platform for media agencies. He was instrumental in creating the first and largest demand-side digital trading business, the rapid success of which led to the creation of Xaxis.

Before leading the MIG, Brian was Vice President of Product Management and Director of Product Marketing at 24/7 Real Media, a global media and technology firm acquired by WPP in 2007. Brian has over 15 years of experience in advertising and technology.

Brian has a BA from the University of Pennsylvania and an MBA from Columbia Business School. He is regularly quoted in digital marketing publications and has been a featured speaker at various industry conferences. Brian sits on the WPP Digital Advisory Board and the GroupM Global Digital Executive Committee.