NEW YORK (AP) — As investors question just how much Facebook is worth, a study from Internet research firm comScore suggests that marketing on the world’s most populous online social network can help increase sales.

The report released Tuesday found that people who were fans of Starbucks and Target, or friends of those fans, were more likely to buy something than those who were not fans. People become fans by hitting a “like” button for a brand’s Facebook page and receiving updates about that brand mixed in with content shared by their friends.