Katia Beauchamp and Hayley Barna
40u40 retail katia beauchamp hayley barna NEW
Beauchamp (left) and Barna (right)
Age: Barna, 29; Beauchamp, 29

Co-founders and co-CEOs, Birchbox

Call it the deal of the month club 2.0. For $10 a month, these two Harvard Business School graduates deliver an assortment of cosmetic, grooming and lifestyle product samples to your home--heaven for beauty junkies. If you like what you try, you can buy a full-size version from the Birchbox website, delighting cosmetics manufacturers. Launched in September 2010, Barna and Beauchamp extended their business into men's products in April and now have 130 employees and more than 100,000 members--and, exhibiting the ultimate proof of a pioneering idea, a clutch of copycats.

--C.K.


- Last updated October 11 2012 04:33 PM ET
Join the Conversation
Fortune's 40 Under 40

Who are 2012's young business stars? We've got the CEO of a blue-chip beer brand, an airline CEO who just placed the largest order in commercial aviation history, and Warren Buffett's new prodigy, among the Silicon Valley hotshots and others.

Market indexes are shown in real time, except for the DJIA, which is delayed by two minutes. All times are ET. Disclaimer LIBOR Warning: Neither BBA Enterprises Limited, nor the BBA LIBOR Contributor Banks, nor Reuters, can be held liable for any irregularity or inaccuracy of BBA LIBOR. Disclaimer. Morningstar: © 2014 Morningstar, Inc. All Rights Reserved. Disclaimer The Dow Jones IndexesSM are proprietary to and distributed by Dow Jones & Company, Inc. and have been licensed for use. All content of the Dow Jones IndexesSM © 2014 is proprietary to Dow Jones & Company, Inc. Chicago Mercantile Association. The market data is the property of Chicago Mercantile Exchange Inc. and its licensors. All rights reserved. FactSet Research Systems Inc. 2014. All rights reserved. Most stock quote data provided by BATS.