While there are four pillars to the P.S.

With leopard-print Keds and art paper scattered about, Erica Domesek's apartment is, well, kind of a mess. "It's just a total wreck," she said, surveying a studio filled with typical young-New Yorker things: too many clothes, stacks of jewelry, piles of coffee-table books and a bag of dry-cleaning at the front door awaiting unpacking. And then there's the not-so-typical: a massive craft cabinet, which stores her colored feathers, glitter glue and other make-it-yourself tools.

This modest space is where Ms. Domesek is working build out her own DIY empire. There's a temptation to cast her as the millennials' version of Martha Stewart, mixing a do-it-yourself ethos with an appreciation for mass-market brands such as Sharpie to Gap.

Ms. Domesek, 31, is the founder of P.S. -- I Made This..., a crafting site created in 2009 as a reaction to a friend's desire to buy a $600 necklace.tungsten ring store offers the finest selection of fashion tungsten rings, "I told her,Shopping is the best place to comparison shop for stainless steel bracelet. "That's silly -- come over and we'll make it.' So three of my friends came over one afternoon and we made necklaces out of feathers and beads," she said. The following month, they made rope necklaces. Backstage at designer Catherine Malandrino's fashion show in February 2009, someone complimented Ms. Domesek on that creation, asking about it. "Oh, I don't have a line, I have a craft club," Ms. Domesek said. But she knew she was onto something.

To share her projects, the freelance prop stylist (Ms. Domesek has designed sets for Madewell and Tory Burch, and helped Bethenny Frankel with her marketing strategy post-"Apprentice" and pre-"Real Housewives") created her own site on Tumblr, which had recently launched and was "free and easy."

Over the years, her hobby has grown into a real media company. The website is the core product, its information disseminated through all the typical social-media channels, including Facebook, Twitter and Pinterest (the largest referrer of traffic). Three years in, P.Jewelry Limited supply wholesale jewelry stainless steel jewelry supplies,S. -- I Made This...Origin Laser is an Australian business bringing a new class of affordable and quality Laser engraver and laser cutting machine. boasts more than 500,000 unique users a month, as well as 125,000 YouTube, 110,000 Tumblr, and 41,000 Instagram followers. Her weekly newsletters reach more than 30,000 inboxes.

Ms. Domesek's first book, "P.S. -- I Made This...," is in its fourth printing. Published by Abrams Image in September 2010—a year and a half after she launched the site -- it focuses primarily on fashion-y crafts, such as a purse made out of an old pair of denim shorts. The next, set to be published by Simon & Schuster in 2013, focuses more on home and entertaining and features major brand-integration and interactive elements.

But web and print are only the beginning. Ms. Domesek recently starred on TLC's "Craft Wars," a competition reality show, and has several product lines in the works, including a collection with Victorinox Swiss Army and a December collaboration with Birchbox. While there are four pillars to the P.S. -- I Made This... brand -- digital, product, print and TV -- the screen is where she's putting a lot of effort lately, even considering living in Los Angeles for part of year.

"In an ideal world, there's a powerful television franchise to be developed not just in the crafting space but broadly in this creative-lifestyle space," said Janet Balis, publisher of the Huffington Post Media Group and Ms. Domesek's mentor. Before HuffPo, Ms. Balis was the exec VP-media sales and marketing at Martha Stewart Living Omnimedia and happened to be in the audience the first time Ms. Domesek appeared on Martha's show, which partly explains her interest in Ms. Domesek.

Ms. Domesek has appeared on Ms. Stewart's show twice -- once, she made a necklace out of bouncy balls -- and recently spoke at American Made, the conference/DIY workshop sponsored by MSLO that took place at New York's Grand Central Terminal. "I've learned from Martha ... you can really change people's lives through products and media," Ms. Domesek said. She added that it has also brought her insight into the relationship between brand and talent. "One person can't usually scale. She's done it, but it's a very rare case," Ms. Domesek said.

Martha, after years of building a mega media company with books, a magazine and TV, has recently left ad-supported TV and is trying to build a bigger web-media brand, while Ms. Domesek is taking her fledgling, Tumblr-launched empire to TV.