Recognize the woman in the picture above? You might not. She's frowning, for one, and she's wearing black leather.

She's the T-Mobile Girl, a.k.a. Carly Foulkes, and last time you saw her she was dressed in pink and using a cheerful approach to sell the carrier's services. The darker image in the new ad spots–dubbed the "alter ego" campaign—are part of T-Mobile's effort to rebrand itself as more "edgy" and in the process attract more customers.

There's a good lesson here for small business owners: There are times when it makes sense to re-invent your brand, turn your existing marketing strategy on its head, and capture a new user base. But execution is everything.

T-Mobile wants to make a point about 4G speeds. In a hotly contested battle, AT&T, Sprint, Verizon, and T-Mobile are wooing new customers with the promise of data speeds around 5-20Mbps or higher. Yet, claiming to offer 4G and delivering that speed are different things. No carrier has consistently provided super-fast speeds in every town, especially if you connect in a busy area or far from the tower.

According to Peter DeLuca, the senior vice president of brand, advertising, and communications at T-Mobile, the company wanted a more "in your face" campaign that makes a stronger assertion about its network speed—something competitors have attacked. It's no surprise that T-Mobile is trying to get more aggressive with its image—the company is in transition mode (read: losing market share).

The result makes you do a double-take, but that's about it. The notion of speed, apparently, is supposed to come from the custom Ducati motorcycle on which Foulkes rides away as the words "No More Mr. Nice Girl" appear on screen. DeLuca says the new "Alter Ego" ads and related marketing will cost $200M and will run most of the summer.

Should T-Mobile have gone with a concept that was truly controversial or outright dark? Given the risks, it's perhaps understandable why it didn't.

Look at the fallout from Groupon's Super Bowl ad, for example. The ad "starring" Timothy Hutton fell flat almost immediately. Hutton begins by talking about the plight of Tibet, a so-called fourth-world country that is barely surviving on subsistence farming. Then he sits down to a meal of Tibetan food in a Chicago restaurant and brags about how cheap it was because of a great Groupon deal.

YouTube commenters were merciless, suggesting that Groupon might try a new campaign involving a woman in a mink coat beating baby seals. Most just didn't find the spot funny. The marketing message came off as insensitive, not edgy.

That's not to say controversy never works. GoDaddy has cleaned up its act lately, but several older ads (like the infamous Superbowl ad from 2005 featuring Nikki Capelli in a tiny shirt) led to an initial outcry but ultimately paid off. It created just the right amount of chatter. In fact, GoDaddy went from being an obscure ISP to a household brand.

Want to cop an attitude in your next marketing campaign? Before you do anything, make sure you know your customers. And make sure you test your idea on a small scale before you do a full roll-out.

DeLuca adds the importance of getting your message right: A darker bent only works if it supports the message you want to convey. Whether or not it was ultimately successful, I'd imagine T-Mobile's message is, "We're tougher than we look–and we're going to set the record straight."

Maybe a bolder, leather-wearing, motorcycle-riding woman is enough to convey it. If anything, it might help Foulkes get more attention for her upcoming FX show.