You can find the UK office for AppNexus in London. Pick up the phone and give them a call on 0203 5300 439.
AppNexus is a New York company which specialises in online advertising. The company’s technology is used as a platform for billions of ads on the internet, integrating with services such as DoubleClick by Google.
Essentially, AppNexus allows agencies to purchase display advertising space depending on a number of criteria, such as the location of the user. Sellers can also use AppNexus to sell advertising space on their website in a similar fashion.