February 6, 2020 Michael G. Barrett Chief Executive Officer Rubicon Project, Inc. 12181 Bluff Creek Drive, 4th Floor Los Angeles, CA 90094 Re: Rubicon Project, Inc. Registration Statement on Form S-4 Filed January 30, 2020 File No. 333-236174 Dear Mr. Barrett: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 460 and 461 regarding requests for acceleration. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Please contact Edwin Kim, Attorney-Advisor, at (202) 551-3297 or Jan Woo, Legal Branch Chief, at (202) 551-3453 with any questions. Sincerely, Division of Corporation Finance Office of Technology cc: Andrew Friedman, Esq.