Online dating has shed its stigma, and is now the most popular way of meeting a partner, other than through friends.
But claims from such sites that they offer a science-based approach with sophisticated algorithm-based matching shouldn't be taken too serioiusly, say researchers.
"Online dating is definitely a new and much needed twist on relationships," says Harry Reis of the University of Rochester.
"The internet holds great promise for helping adults form healthy and supportive romantic partnerships, and those relationships are one of the best predictors of emotional and physical health."
He and his colleagues reviewed more than 400 psychology studies and public interest surveys - and found an enormous boom in online dating over the last 20 years.
In the early 1990s, fewer than one percent of the population met partners through printed personal advertisements or the like - but by 2007-2009, 22 percent of heterosexual couples and 61 percent of same-sex couples had found their partners through the web. And the numbers continue to rise.
"online dating has entered the mainstream, and it is fast shedding any lingering social stigma," write the authors.
Men, it seems, tend to shop around more than women, viewing three times as many potential partners, and are 40 percent more likely to initiate contact.
But this isn't always a good thing: people can become ridiculously picky, say the authors, focusing exclusively on a narrow set of criteria like attractiveness or interests. Corresponding by computer for weeks or months before meeting face-to-face creates unrealistic expectations.
And those looking for a soulmate are probably worth avoiding.
"People with strong beliefs in romantic destiny (sometimes called soulmate beliefs) - that a relationship between two people either is or is not 'meant to be' - are especially likely to exit a romantic relationship when problems arise… and to become vengeful in response to partner aggression when they feel insecure in the relationship," the authors write.
In any case, they say, promises of 'scientific' matching appear to be so much hot air. There are no published, peer-reviewed papers – or internet postings, for that matter – describing just how the sites purport to do this. Indeed, they all claim that their methods are proprietary secrets.
Still, the consensus seems to be that it's worth a try. As one online dater told the researchers: "Where else can you go in a matter of 20 minutes [and] look at 200 women who are single and want to go on dates?"