In the 18th edition of her etiquette guide, Emily Post acknowledges that we're seeing "wide diversity in the family constellation" and touches upon the sensitivity of singlehood: "Some people still have trouble realizing that alone doesn't automatically mean lonely or searching for a mate." Post outlines protocols for occasions that celebrate single-parent families and same-sex couples but fails to include suggestions for people who are single and childless.

When will barometers of celebration reflect the growing number of singletons?

I decided to pose that question to Hallmark, which seems to have a greeting card for every imaginable occasion. Jaci Twidwell, Hallmark's publicity manager, told me, "We don't have any new greeting cards specific to milestones in a single adult's life. But we do have cards for occasions that might be celebrated with a little more energy by a single person who doesn't have things like wedding anniversaries to celebrate. New Home, New Job or New Aunt would be examples."

This answer hints at an underlying judgment: commemorations of the individual are placeholders for more significant achievements in life. Our worth, it seems, is still measured by the people we marry and the children we bear, despite the fact that an increasing number of adults choose to live alone.

Travel giants feature themed vacations, but few incorporate trips for the solo traveler. Expedia offers romantic, adventure, gay, and green vacations, so I asked whether the company planned to tack on trips for the solitary tourist. A rep from the company responded, "Expedia doesn't have any data or anecdotal information to share with regards to single/solo travelers."

Still, there are some signs of hope. Smaller companies and those offering customizable products are more adept at courting single clients. Abercrombie and Kent caters to solitary travelers with "Solo Vacations," sending guided groups of globetrotters all over the world. Other outfitters, like New York City-based Absolute Travel, believe that "exploring the world on your own brings freedom, reflection, and flexibility".

Some entities exclusively serve single travelers. Singles Travel International matches roommates and, when possible, persuades lodgings to waive single traveler supplements. For 20 years, its affiliate, A Single Gourmet, has provided independent foodies the chance to dine with new friends.

Several cookbooks, including The Pleasure of Cooking for One and Serve Yourself, cater to solitary chefs, and a growing number of grocery stores offer portions for one. The Onion spoofed lonely diners with "Stouffers to Include Suicide Prevention Tips on Single Serve Microwaveable Meals." Whether zapping a Lean Cuisine or chopping veggies, adult singletons will invariably note an uptick in television shows featuring single professionals (The Mindy Project and New Girl) and modern family units (Modern Family, The New Normal, and Ben & Kate). Self-help books and love coaches are becoming more popular, too, as I explored in my last piece for The Sexes, "What I Learned from Hiring a Love Coach."