The Who-To-Follow system at Twitter is an algorithmic data product that recommends accounts for Twitter users to follow. Building the system involved algorithmic, analytics, operational, and experimental challenges; OR and analytics techniques played a key role. This product has had significant direct impact on Twitter's growth and the quality of user engagement, as well as being a major driver of revenue. Over 1/8 of all new connections on the Twitter network are directly due to this system, and a substantial majority of Twitter's revenue comes from its Promoted Products, for which this system was foundational. To place this contribution into perspective, Twitter is now a publicly traded company with a market cap over $30 Billion, a projected annual revenue close to $1 Billion, and over 240 Million active users.
Organization overview: Slide # 4
Problem and challenges: Slide # 22
Approach and methodology: Slide # 29
Results, impact, and conclusions: Slide # 66