The site, which launched in the UK in 2008, ran a TV campaign showing eight couples with onscreen text showing their names and the date on which they were matched by eHarmony.

A voiceover stated: “It’s no surprise that over 4 million Americans get married each year. But what might surprise you is that 2% of those newlyweds said they met on eHarmony. And now we’re in the UK.”

Five viewers complained to the Advertising Standards Authority to challenge the claim that 2% of US newlyweds met via the site. Another three complainants, who had attempted to use the service, said the ad was misleading because it did not make clear there were “significant conditions” attached to obtaining free matches.

EHarmony said the 2% figure was extrapolated from an online study of 7,000 respondents undertaken by an independent market research company. It added that the only eligibility restrictions at the outset of its in-depth questionnaire for users were regarding age and marital status.

The ASA ruled eHarmony’s ad was misleading because it had made an “absolute claim” that suggested a “definitive figure” of marriages based on an extrapolated 2007 online survey. It said the ad also failed to make clear that in 20% of cases it was unable to find a match for people who registered.

Sean Cornwell, VP International Markets at eHarmony, said: “We believe the TV ads accurately portrayed the eHarmony service, but we respect the ASA’s request for more detail. We are amending the ads to indicate that eHarmony does have some eligibility requirements for users and to clarify that the claim that an average of 236 eHarmony users married each day in America is based on a study conducted by Harris Interactive for eHarmony in 2007. The ASA did not disagree with the results of the research. “