How many times has it happened&;#63; You’re on your computer‚ searching for a particular article‚ a hard-to-find fact‚ or a story you vaguely remember‚ and just when you seem to have discovered the exact right thing‚ a paywall descends. “$1 for Six Months.” “Save 40% on Year 1.” “Here’s Your Premium Digital Offer.” “Already a subscriber&;#63;” Hmm‚ no. Now you’re faced with that old dilemma: to pay or not to pay. (Yes‚ you may face this very dilemma reading this story in The Atlantic.) And it’s...