Criteo

Criteo provides solid, effective retargeting, so your marketing is reaching people who have already engaged with your brand. Along with retargeting across different networks and devices, Criteo also helps you drive personalised recommendations, increase the average lifetime value of a customer, re-engage those who might have dropped off, and send targeted promotions to those that fit within relevant segments. Their remarketing works on a set CPC basis, covering cross-device engagement so you can maximise your touch-points with the most relevant visitors.

http://www.criteo.com