Forbes: Reinvention or Regression?, launched in 1996 when most media companies hadn’t a clue about the Web, was once held up as the poster child for how to build an old-media brand online. But with questions about the real value of its aggressive traffic growth and with its investors unhappy about the site’s financial returns, is radically reinventing itself.

Last week, the site ran its first ad under AdVoice, a new program that lets advertisers run their own blogs that appear alongside Forbes’ regular editorial contributors. SAP was the first to take up Forbes on the offer.

The transformation, the brainchild of onetime Forbes staffer and digital entrepreneur Lewis DVorkin, whom Forbes Media hired in June as its chief product officer (his title in itself a sign it’s no longer business as usual), doesn’t end there.

Borrowing from DVorkin’s True/Slant blogging platform, which Forbes bought (for an undisclosed sum) as a way to hire DVorkin, Forbes has begun giving advertisers and outside contributors a greater voice in the magazine and on the Web site.

As Dvorkin has explained it, the approach recognizes consumers’ desire to be on an equal footing with journalists and marketers’ demand to reach consumers more effectively.

It’s also a way to cut expenses, getting content at a lower cost but, more heretically, putting advertisers on the same plane as contributors.

Indeed, socked by the recession, the slow growth of old-line business publications, and the disappointing results of its once-vaunted Web ambitions, Forbes has made deep staff cuts, sold off assets and killed some of its magazine spin-offs. A large number of staff members have departed along the way, either voluntarily or through layoffs, including notables like Carl Lavin, Lucy Maher, Paul Maidment, Tunku Varadarajan and Elisabeth Eaves.

Forbes declined to make DVorkin available for comment.

Meanwhile, editors have been pressured to increasingly rely on nonpaid contributors for the Web, with the goal, as one former editor put it, “of not paying anything for content.”

Traffic to the site has plunged 21 percent to 11.5 million monthly uniques from 14.5 million in the past six months, per comScore.

From the outside, the experiment is being closely watched for both how Forbes will filter and integrate non-staff written content and how its audience will react. Is the move just another retrenchment or an effective new model for increasing margins in a CPM-challenged world?

Robin Steinberg, svp, director of print investment and activation, MediaVest, gave Forbes credit for thinking differently, but wondered how business news consumers in particular would react to the potential confusion surrounding the change in the historic brand.

Scott Daly, evp, executive media director at Dentsu America, said in adopting the more inclusive model, Forbes is trying to employ the model of digital-only sites like HuffPo, which have a lower content cost.

“At one point in my career, I would have completely crapped on this strategy,” he wrote in an e-mail. “Now I feel more like it’s a compromise that is reflective of how media (content, opinions, ads) are consumed today.”