The question first sat up and begged when an executive from an anti-spam start-up told me he had counted 400 competing products and services - from the slick to the amateurish - before deciding that he had counted enough.And the same question fairly screamed at me one day recently when I received three separate story pitches from yet three more anti-spam start-ups, none of which had previously registered on my anti-spam radar screen. (That monitor looks like one of those air-traffic controller panels you see in the movie "Pushing Tin," just before the guy juggling all the planes goes bonkers.)The question is, how can any anti-spam vendor hope to get enough attention from the press and potential customers to survive the bloody shakeout that's coming soon to this market?I asked Roger Matus, CEO of\u00a0Audiotrieve, which recently launched InBoxer for Outlook. InBoxer is an anti-spam client application - server version coming later this year - that's based on Bayesian mathematics and built by a group of Dragon Systems expatriates who weren't even thinking about spam when they started the company. Just to be mean, I told Matus about the other fellow giving up on his count after No. 400."That scares the heck out of me," he says.Not that there was any trembling in his voice. Matus quickly assumed the entrepreneur's classically confident pose: "You don't have to be No. 1 or No. 2 to turn a profit," he says.But you can't be No. 37 either, and someone out there will be, not to mention the whole pack of nobodies trailing even further."There's a low barrier of entry to call yourself an anti-spam product," Matus says. "That does not mean all anti-spam products are created equal."He's not fond of the rules-based filters or challenge-response systems, which only stands to reason, because InBoxer is neither.So how exactly does a member of this exceptionally crowded field go about breaking free of the pack?One way might be to generate oodles of free publicity by getting your little ol' self sued by a big ol' brand-name company. But that ticket's been punched already by Seattle's Spam Arrest, which earlier this month found itself the target of legal action by Hormel, maker of the lunch meat and owner of the Spam trademark. The publicity Spam Arrest is reaping would make a good MasterCard commercial.As for Audiotrieve and InBoxer, Matus says the company must first leave that blob of 400 behind and earn a spot in the Top 20 through good word of mouth and "influencing the influencers." Then it's an old-fashioned marketing game.They also need for "people to agree on exactly what they want in a spam filter," he says, because when they do he's confident the consensus will be to InBoxer's benefit. His company believes that false positives are unacceptable, legitimate senders shouldn't have to jump through hoops and that an anti-spam product needs to be able to tell the difference between a welcome message and junk even if they're from the same sender.He's also realistic about the need for an exit strategy."I don't have the false expectation that we're going to be in the anti-spam business in 10 years," he says.Correction: Wrong number on InfoneLast week's column regarding Infone contained an egregious error about the price that this new information service charges callers.The correct price is 89 cents - total - for the first 15 minutes, plus 5 cents per minute thereafter.My apologies to Infone. And my thanks to all who wrote to point out the mistake without calling me any names.If you do want to call me names, the address is email@example.com.