To be sure, the internet's the most measurable advertising medium in history. But that doesn't mean publishers can't fix the numbers. During the last internet boom, they'd count hits, rather than pageviews, or inflate revenue numbers with barter advertising deals. Advertisers, and the audit companies, are more sophisticated now, but so are tricky publishers. A Harvard doctoral student says audience numbers of three high-profile sites — Concierge.com, a travel title owned by Conde Nast, Forbes.com's auto site, and entertainment hub Heavy.com — have been spiked by use of pop-ups. Heavy — with 6.9m unique visitors in November, according to Comscore — dwarfs sites such as College Humor that seem, anecdotally, more popular. I've always wondered how Heavy puffs up its numbers; now we know.