This week Slate celebrates its birthday with retrospectives, illustrations of cakes, and other indulgences befitting a 10-year-old. Back in May, Jack Shafer took a swipe at magazine anniversaries, bemoaning the tendency to forgo real content every five years in favor of a little "auto-editorial stimulation." "Like birthday parties thrown by the birthday boy," Shafer argued, "anniversary issues tend to overindulge the honoree." So, why do they persist? "Nobody in magazine publishing will say no to anniversary issues until readers do," Shafer wrote, adding "I don't think that day has arrived." Lucky for us.