AdRoll is a retargeting and prospecting platform for advertisers.
Publishes cross-channel ad campaigns to over 500 ad exchanges, including Facebook, Twitter, Instagram, and Google.
Has proprietary real-time bidding algorithm, so you don’t overpay for ad space or placement.
Offers prospecting tool so you can find and market to new audiences who match your current ones.
Allows for automation and high data portability.
Since July, 2018, Google Ad Manager combines former DoubleClick for Publishers (DFP) and DoubleClick Ad Exchange (DCAE) products. It is a comprehensive hosted ad serving platform that streamlines your ad management, whether you deliver ads to websites, mobile webpages, mobile apps, games, or a combination. Yes, it can be used as an ad server but it also provides a variety of features for managing the sales process of online ads using a publisher's dedicated sales team.
It is a powerfull tool, but not the only tool you can use more effectively with a bit of Improvado assistance.