And NAD agreed with Match's argument that, if matches made on other sites it ran during the period were counted, "the actual difference within the sample is even smaller than reported, or possibly favors Match." The ad evaluators dispatched e Harmony's other challenged claims with similar Talmudic elan.

Nearly 40 is the new 30, and 60 rounds down to farther than even a lovelorn mathematician could countenance. Words such as Do online-dating sites ever play the same game?

Yes, according to the arbiters at the National Advertising Division of the Council of Better Business Bureaus, who last week dinged e Harmony for stretching some of its own supposedly scientific claims to the breaking point.

NAD sided with Match.com's challenge to some of e Harmony's most familiar claims, including: "Ranks 1st in most satisfied marriages." "Ranks 1st in most enduring marriages." NAD's conclusion?

This is the fourth round between the companies since 2006.

Twice, Match has challenged e Harmony, and won at least a split decision.

While the findings e Harmony cited seem "methodologically sound," they didn't support the company's claims about its relative success.NAD said e Harmony has already dropped another claim Match challenged: calling one of its main studies "independent," even though lead author John Cacioppo is a scientific adviser to the company.One way or another, almost all dating sites claim to use sophisticated algorithms to match their clients, a promise that has helped the industry come to measure revenue in the billions of dollars.But this isn't a dispute over e Harmony's claims about its scientific approach to finding you a soulmate. Citing Cacioppo's study and other data, e Harmony argued that it has "the most marriages per user or per visitor as compared to its competitors," NAD said.Twice, e Harmony has returned the favor, though once it aimed at a Match affiliate, Match's parent company also owns OKCupid and other dating sites.