Abstract: In accordance with an embodiment, described herein are a system and method for providing advertisement content in a media content or streaming environment. A media device, operating as a client device, can receive and play media content provided by a media server. An advertisement server can be used to determine advertisements or other promoted content to be delivered to the client in connection with the provided media content. An optimization service extends the advertisement server's in-built delivery optimization engine or functionality, for example by providing line-item tweaks to manipulate advertisement priority, effective price, or creative rotations; or by providing real-time bidding or pricing tweaks to allow content provider advertisements to compete dynamically with advertisements trafficked by the advertisement server. The advertisement delivery process can be adjusted for particular users, or to address behavioral attributes.