Every once in a while, Kyle Robidoux spots a homeless person " illegally " hawking newspapers at the Hynes Convention Center T — arms full of the Back Bay Courant, Spare Change, and even the Boston Phoenix. But when he sees someone with a stack of Whats Up, the South End bimonthly magazine, he puts a stop to it instantly.

" There’s a good amount of abusing the system going on, " says Robidoux, who directs the vendor program for Whats Up.

Robidoux doesn’t begrudge the homeless the chance to make a buck. He just worries about his organization’s credibility. Whats Up is a largely volunteer-run street newspaper that tracks the local entertainment and activist scenes, and then employs homeless and poor people to sell its issues. Bona fide Whats Up vendors — identified by black-and-white badges that bear their names — earn 75 cents for every $1 magazine they sell. As Robidoux puts it, " We want to empower the homeless and disadvantaged to help themselves, " not to perpetrate a con on unsuspecting readers.

Then again, Whats Up readers may care less how they get their copies, so long as they get them. The nonprofit ’zine boasts enough for the young and socially aware — the current April/May 2003 edition includes an interview with Boston poet Letta Neely; a how-to guide on making homemade brew; a think piece on hip-hop; and an article detailing the loss of drug-treatment programs — that Robidoux doubts most readers even buy the publication for the sake of its cause. He says, " We feel very strongly that a majority of our readers buy it for the content only. "

But it’s precisely this mix that’s made Whats Up such a hit. The six-year-old publication — inspired by the ultimate street rag, the London-based Big Issue — will ramp up production and go monthly in June. The move is meant to strengthen the magazine’s mission to provide " transitional employment to people who are homeless or in need of income. " According to Robidoux, most street newspapers don’t achieve financial success unless they publish every month. Now that the paper will be coming out more often, its material will be more current and vendors will hawk it with greater enthusiasm. Indeed, the most common refrain that Robidoux encounters when recruiting potential vendors is that the magazine, at six issues a year, doesn’t allow them to make enough money. On average, Whats Up’s 22 registered vendors earn up to $1000 on each bimonthly issue, which they typically use to find housing, or buy food, clothing, and T tokens.

Now that Whats Up is switching to a monthly schedule, Robidoux has inched one step closer to his dream of selling the magazine through street hawkers only. Right now, you can find a Whats Up vendor hawking papers in Harvard, Central, and Davis Squares, as well as in Boston Common, Downtown Crossing, and on Newbury Street. But vendors — the legitimate kind, that is — sell just 3300 of an edition’s 7500 copies. The rest are available at 55 independent bookstores, record stores, and cafés in and around the city. " Down the road, " Robidoux muses, " it’d be wonderful if we operated strictly via vendors. " After all, he says, " That’s our mission, to help the homeless. "

Until then, Robidoux offers up a few words of advice: " Purchase the magazine from vendors with a Whats Up badge. That’s our stamp of approval. "

Whats Up will host a special fundraiser in honor of its switch to a monthly schedule this Sunday, June 1, at 6 p.m., at the Haley House soup kitchen, 23 Dartmouth Street, in the South End. Tickets are $10 for a three-course dinner. Contact Whats Up at (617) 267-1575 or check out its Web site at www.whatsupmagazine.org