DETROIT -- While Mountain Dew is a monster brand in its own right, Diet Mountain Dew is no longer an also-ran, Advertising Age reported. These days, the diet soda has its own tagline, a marketing manager and dedicated budget, and sponsorship of Dale Earnhardt Jr.'s NASCAR car -- all of which is leading to sales success where other soda brands are faltering.

Diet Mountain Dew debuted in 1988 and became one of the top 10 soda brands in 2005. Its sales volume increased 2 percent in 2011, excluding fountain sales, according to the report, which cited Beverage Digest data.

"We attribute this to the strength of the Dew brand with male consumers," a brand spokeswoman said. "The brand halo from base Dew seems to counter the negative 'diet' perception." Senior Marketing Manager Emily Silver serves as the first dedicated manager for Diet Mountain Dew, and it boasts its own tagline: "Yeah, it tastes that good," which is meant to let customers know that its flavor is on par with regular Mountain Dew. The tagline will appear in a series of national commercials this year, according to the report.

"We hadn't put a lot of resources behind [Diet Mountain Dew]," Brett O'Brien, vice president of marketing for Mountain Dew and flavored carbonated drinks, told Advertising Age. "It was something that you found and then you were in this exclusive club, because we didn't talk about it much. As that exclusive club grew bigger and bigger, it became clear we had to put some dedicated resources against it."

Diet Mountain Dew has a prime spot as the sponsor of NASCAR driver Dale Earnhardt Jr., who won second place in this year's Daytona 500 race. "There were T-shirts, hats and backpacks everywhere. You can just imagine the awareness that's going to come from that," said Silver. "[Dale] empowers the target we're trying to reach. He's clearly in that demographic; he's switching to Diet in his own life."

A new commercial spot featuring Earnhardt and the Diet Mountain Dew car is set to begin airing this month. In addition, the brand has partnered with ESPN's "Fuel the Frenzy" college basketball promotion.

Overall, media spending is set to increase by 50 percent this year, the report noted.

"We've got a lot of runway," said O'Brien. "We're by no means at a point where it's about trying to get current users to drink more. It's about bringing in new users. It's sort of this new drink that's been around a long time."