Although we're not judgmental about material things like clothes or cars, we do confess to judging a book by its cover. But these days, when everyone's Kindle case is the same color, that's harder to do.

The judging starts when you are young. In elementary school, reading groups are color-coded according to "reading readiness." Yellows are independent readers; blues need the teacher's help, and everyone knows what group you are in. In high school, kids in AP English read Things Fall Apart by Chinua Achebe, while the grade-level readers plow through Suck It Up by Brian Meehl. Everyone knows what class you are in.

Today, when we walk down the aisle of a plane or train looking for our seats, we can't help but glance at what people are reading and form snap judgments. Seat 8C is reading USA Today: He's unprepared; he had to take the free newspaper from his hotel. The woman with the Harlequin romance: At least she knows what she likes. The student reading Ulysses: Who's he kidding? He'll fall asleep after five pages.

When we visit someone's home, the bookshelves give us another opportunity to assess their interests and intellect. If you judge us by what's on our shelves — Selected Poems of Elizabeth Barrett Browning, the glossy art book on Frank Stella, and How to Win at Tournament Bridge — we might appear pretty erudite. But what you don't know is that our shelves haven't changed in 30 years, and we haven't opened that book of poems since college. Our books are more museum display than current commentary.

What's current is on our e-readers, and no one can judge us by what we are reading because they can't see the cover. An e-reader lets us secretly read trash, and we, along with millions of other women, are doing just that.

We both gave in to the lure of the hottest new book, Fifty Shades of Grey. Suburban moms were missing the carpool pickup because they were engrossed in its sex scenes. When a friend's book club abandoned Ann Patchett and started analyzing sadomasochism, we knew we were missing something. How could we resist downloading this "mommy porn," especially since we could do so anonymously? We would have been embarrassed to ask a bookstore clerk to ring up a hard copy of Fifty Shades of Gray, but it was easy to "add to cart" for $9.99.

Porn aside, we don't have many books on our e-readers yet. We prefer to pick up and hold an actual book. We used to find any excuse to go to the bookstore. We enjoyed flipping through the colorful photos in Bobby Flay's Mesa Cookbook, offering travel advice to a woman planning a trip to Costa Rica, and complaining to another mom about the college application process in the SAT study guide aisle. But there's nowhere to do that in our neighborhood anymore. Three large bookstores have closed, and browsing on Amazon is not the same.

Joyce Eisenberg and Ellen Scolnic, also known as the Word Mavens, are the coauthors of the Dictionary of Jewish Words. Their blog is