Mark Zuckerberg has vetoed a “dislike” button for his site, “suggesting that the world is negative enough.” However, much like Tumblr did earlier this month, Facebook will be adding call-to-action features such as “Shop Now,” “Book Now,” “Sign Up,” and “Play Game.” Page owners will be able to add these buttons to drive business, and early tests were reportedly a success: Dollar Shave Club’s “Sign Up” button “delivered a 250% higher conversion rate versus other comparable social placements.” (MediaPost)