Brain Pickings’ Maria Popova is a little like the brainier counterpart to the Oatmeal’s Matthew Inman: She’s got her haters, but she’s also hugely popular, to the tune of 500,000 monthly visitors to her website. Fans like Biz Stone and William Gibson come for her eclectic array of offerings; many, like Princeton professor Anne-Marie Slaughter, fork over regular donations to keep the site running without ads. (Ms. Slaughter has compared it to supporting your local public radio station.)
But there’s something Ms. Popova doesn’t mention in her appeals to donors, amid her talk of operating “ad-free.” She might not run banner ads, but she appears to earn income from affiliate links. You read a glowing review, you click through to order the book, and Ms. Popova gets a commission.