Social network Pinterest has purchased a startup that powers a machine-learning recommendation engine. The seven-person company Kosei, which was founded less than a year ago, has developed a graph that understands the relationships between millions of products. Image-driven Pinterest can use this recommendation engine to help detect spam, recommend more relevant pins, and target its advertising. Pinterest just rolled out advertising on its platform earlier this month. Continue reading Pinterest Acquires Kosei to Help Improve Pin Recommendations