[joe42]

Not the first Facebook app to do this. For example (link now deleted, though), http://news.ycombinator.com/item?id=2334990, which I remember because I posted this comment:

"Oh, I just marked you/everyone to see if you had marked me, I wasn't being serious."

[Yaggo]

"Yeah me too". Solution: "I'm serious" button after first match a.k.a two-step matching.

[gzavitz]

Problem: "I only marked the 'I'm serious' button to see if you were serious, I wasn't really serious."

[robgibbons]

Solution: "I'm REALLY Serious, and I'm an Asshole" button

[Ganthor]

Joysper.com is another similar app. It's gotten quite a bit of traction at the few major Canadian universities it has been rolled out at.

[InclinedPlane]

This is a fundamental problem in this area. Flirting exists for a reason, and that reason is because relationships are smooth curves not step functions. And the seriousness of relationship issues (which can easily be as heartbreaking as losing a family member) means that it's typically necessary to begin only with the most tenuous of bonds between people who might love each other.

Trying to force this subtle and enormously complex social interaction into a clunky machine is just asking for disappointment and failure.

[klipt]

Nature also lessens this problem by correlating seriousness with physical affection and hormones. Kissing is a much more meaningful signal than texting "I seriously like you".