All's fair in electronic love and dating -- or is it? The battle for hearts and minds of couples seeking their perfect match online has taken a new turn.

If you're a flirty mobile warrior Tindering on the brink or Bumbling from one swipe to the next be aware there's another game in town as Facebook muscles in to place its own tanks on the lawn.

As online dating becomes the virtual norm -- some experts suggest half of British couples will meet that way come the end of the decade -- Facebook's gradual arrival on the dating scene looks set to shake up the market.

Facebook founder Mark Zuckerberg promised at the outset a service designed "for building real long-term relationships -- not just hook-ups."

But rivals are not quaking in their boots just yet, despite the size of the social media giant's global footprint with more than two billion monthly active users, some of whose data it now could leverage for romantic purposes.

Facebook chose Thursday, the eve of Valentine's Day, to explain it had yet to launch its dating service in Europe because Ireland's data protection authorities had inspected on Monday its European HQ in Dublin to collect information to fully assess the privacy impact of the app.

"It's really important that we get the launch of Facebook Dating right so we are taking a bit more time to make sure the product is ready for the European market," the tech giant said in a statement to AFP.

For Didier Rappaport, founder and managing director of popular French dating app Happn -- motto, 'crushes don't fall from the sky', "we've seen nothing change in terms of market share" since Facebook began rolling out its app in the Americas and parts of Asia last year.

He adds a fundamental issue is whether social networks are a good fit for dating.

"Are social networks and meeting up a match? In my view, no, as what marks out a social network is the sharing of information -- whereas dating moves into the intimate sphere," he said.

Julien Pillot, a researcher and lecturer at leading French business school Inseec, said Facebook has "copied everything which worked well on other applications and added two or three functionalities. What interests them is getting users to link in the sharing of private content."

Match-making is big business -- and the gradual rollout Facebook Dating poses a challenge to other platforms looking to make cash from bringing online lovebirds together
Match-making is big business -- and the gradual rollout Facebook Dating poses a challenge to other platforms looking to make cash from bringing online lovebirds together AFP / DENIS CHARLET

A December opinion poll of 21,000 Americans by Piplsay showed only 23 percent of responders would happily let Facebook securely store their personal data on its dating platform.

Clementine Lalande, co-founder of French dating app Once, noted that "the big problem with generalist applications is you end up with a mass of users who don't share the same interest communities."

If Facebook's challengers are not yet professing too much concern at the Californian colossus's arrival that is because they are too busy being wary of Match Group, the US internet firm which has split off from parent and controlling shareholder IAC and which owns dating brands such as Hinge, OKCupid, Match.com, Meetic and, not least, Tinder.

Tinder ranked top for user monetisation in a study across a range of non-game apps last year by specialist data provider AppAnnie, raking in $1.2 billion across the year in a global marked valued at some $2.2 billion.

Jean-Baptiste Bourgeois and Kevin Pasquier, strategic planners with We Are Social digital agency, told AFP that "Tinder has redefined the whole user dating path."

In its basic form, "it is a fairly cunning mechanism which after several swipes limits the user, frustrates him and generates fear of missing a rare pearl" who might be out there.

A way of capturing that pearl or at least reduce one's chances of missing out is to take out a subscription offering wider functionality to move beyond the superficiality of simply chasing an image.

Match Group head Amanda W. Ginsberg says her firm "will not underestimate" Facebook's potential to corner the market, not least given the numbers already on its platform and ease of access.

"But for now we don't see any consequence for any of our brands."

A Tinder spokesman told AFP meanwhile it sees its rivals as general apps popular with young web surfers such as Tik Tok, Snapchat, Netflix and YouTube rather than dedicated dating apps.