The encyclopedia · Product & Design · Product decision · 2010–2015
Twitter's Who-To-Follow engine drove over one-eighth of new follows
A recommendation engine that mined the follow graph and user signals — more than one-eighth of all new Twitter connections trace directly to it.
the move
When Twitter wanted to grow, the obvious barrier was cold start: a new user opens the service and sees nothing to follow. Manual curation does not scale to millions of users, so in 2010 Twitter tested and rolled out 'Who To Follow', a recommendation engine for accounts.
The system scores candidates with a blend of graph analysis — the people you and your network follow — collaborative filtering and live signals, then surfaces them in the sidebar and in follow flows. It is an algorithmic data product built with operations research and analytics, and it was engineered to be evaluated and improved continuously.
The impact was measured, not assumed: more than one-eighth of all new connections on the Twitter network are a direct result of the system, and over 15 percent of active users make a follow from a recommendation. It also became the foundation for Twitter's promoted products, the source of most of its revenue.
The project was a finalist for the 2014 INFORMS Franz Edelman Award, and the Interfaces paper documenting it ran as Twitter was a public company with a market capitalization above $30 billion and projected annual revenue near $1 billion.
why it works
- The follow graph is self-improving: every new edge makes the next recommendation better.
- Recommendations attack the cold-start problem instead of relying on manual curation.
- The same engine powered organic growth and paid promotion, aligning the two businesses.
- Measuring outcomes let Twitter tune the product with experiments rather than opinion.
what transfers
Growth can be designed as a product: a recommendation engine that lowers the cost of the first follow compounds, because every new connection improves the graph for the next user.
what came after
Who-To-Follow became the backbone of Twitter's growth and advertising: over one-eighth of new connections came from it, and the promoted-products business built on it delivered a substantial majority of revenue as Twitter passed a $30 billion market capitalization.
references
- The Who-To-Follow System at Twitter: Strategy, Algorithms, and Revenue Impact
- Twitter's Social Graph Is About To Get Pumped Up. 'Who To Follow' Is Social Steroids
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