A world that was once home to Club Penguin, Nickelodeon, Silly Bandz bracelets and Nerf gun wars is now increasingly populated by Burberry, Poppy by Coach, and Uproar by JC Penney. The tweens are coming of age, and they are ready to spend their parents’ money.

While parents will do without to keep their kids happy, kids will beg for everything that comes down the pike. The tween category generally refers to children ages 8-to-12, but can go as young as 7 and as old as 14. Since this group is not yet brand loyal, marketers are doing all they can to be front and center.

Tweens certainly have their options: from high-end collections from Burberry, Philip Lim and Coach, lines from young celebs like Dream Out Loud by Selena Gomez, and one-offs like Stella McCartney for GapKids, to tween-centric stores like Justice and newly-created private labels like Uproar at JC Penney.

Tweens represent a consumer group with a lot of buying influence, but no money of its own, which means retailers have to appeal to moms and dads, too.

When it comes to apparel, parents say they plan to shop for most of their children's clothing at mass merchants (62%), chain stores (50%), specialty stores (40%), department stores (25%) and off-price stores (23%), according to the Cotton Incorporated Lifestyle Monitor™ survey.

This impressionable group was not immune to the recession, however; the NPD Group reports dollar volume sales of apparel worn by U.S. 7-to-12 year olds totaled $13 billion for the 12 months ending in March, down 4.6% from the previous year.

Despite the slightly bleak economic news, there are still bright spots: Walmart and Target are category leaders, followed by Tween Brands, which was purchased by Dress Barn in November 2009, and operates more than 900 Justice stores in the U.S.

"Tween girls look to Justice as the authority on fashion and styling," says Scott Bracale, president of Tween Brands Marketing Agency. "And we're satisfying mom's need for value."

Tween Brands converted its Limited Too stores to Justice, and then reduced retail prices by 25-30%. Catalog coupons offer an additional 40% off a store item. Justice only carries private label apparel.

JC Penney's new Uproar brand, set to launch in July, is the retailer's first private label geared solely for the tween set.

"The tween customer is an important and growing category for JC Penney," says Kate Coultas, spokesperson. Aside from Uproar, the retailer reaches out to kids with brands that include Arizona, Levi’s and the upcoming exclusive brand from Nastia Liukin, the U.S. Olympic gymnast and five-time medalist, Supergirl by Nastia.

The timing is not coincidental; back-to-school shopping is a key milestone for many retailers. During the recession, children's clothing fared better than other apparel categories, mainly because new items are needed to replace the clothes kids wear out and outgrow. In fact, 79% of respondents to the Monitor survey said they planned to purchase new clothing for their children this fall.

Some of the top items Monitor respondents buy for back-to-school for their kids are shirts (83%), jeans (80%), socks (73%), pants (65%), outerwear (55%), sweaters (48%), activewear (34%), dresses (20%) and skirts (18%).

Coultas says JC Penney also conducted extensive research on tweens and their moms. Among their findings:

--Tweens select apparel items themselves, but moms have a final say in the purchase.
--Color, embellishments and comfort are important factors to tweens; they want to be fashionable, but need functional apparel that allows them to relax and play.
--Price, quality and appropriateness are important factors for moms.

Other retailers who have sensed the importance of the category include Aeropostale, which has launched p.s.; Brooks Brothers, which is in the process of launching a girl’s line, and American Eagle, who recently unveiled 77kids.

Reaching the youth market through ads and social networking can be tricky, though, since middle schoolers are largely considered a group that still needs oversight and protection. The Federal Trade Commission recently launched an ad literacy campaign for tweens to help them understand the ads they see and become smarter consumers.

It is a concern for many; recently, a New Jersey middle school principal gained national attention when he advised parents to protect their kids from cyber bullying by banning them from social networking sites like Facebook.

Tween Brands' Bracale agrees with the educator's thinking. "When the mom thinks of our brand, I want her to think 'great fashion, affordable pricing, emotional connection with my daughter, and safe.' Until we determine the best way to use social media in mom's eyes, we won't go there."

Its Website offers music, screensavers, even a short story to read. Girls can comment on an outfit, but there are no chat rooms, or Facebook or MySpace widgets.

Instead, Justice relies on 11 42-page "catazines" per year that mom and daughter can browse through together. In store, Justice re-creates a tween girl's environment with fixtures matched to her shorter stature, music videos broadcast on plasma screens, and lots of product to peruse.

"Our stores are all about abundance and senses overload,” Barcale says. “We encourage girls to touch and play with the product and throw it back on the table, like she'd do in her room. By the same token, we want to make it easy for mom, so we put color stories and outfits together that let her make quick decisions and help her daughter, too."

Those retailers able to stay ahead of the curve for tweens, while still maintaining quality and value for mom, will reap the rewards as this group ages and cultivates a spending power all its own.