I know I'm not the only one who thinks those Chemistry.com commercials are stupid. They show attractive singles, lamenting about why they were rejected by a rival online dating site.

"We don't know why eHarmony has rejected over a million people looking for love," goes the tag line. "At Chemistry.com, come as you are."

So one would think that eHarmony is loving the rival-bankrolled publicity. Not so, apparently. eHarmony brought charges against Chemistry -- which is a subsidiary of IAC's (NASDAQ:IACI) Match.com -- before the Better Business Bureau's ad council.

The charges aren't about the ads. EHarmony is disputing Chemistry's claim that the questionnaires filled out by Chemistry applicants "predict which single men and women you'll have a relationship and dating chemistry with."

Absent tangible proof, the bureau wound up siding with eHarmony.

I'm not sure why eHarmony would go out of its way to try to quash a competitor's claim, especially one that was indirectly promoting eHarmony as a place for choosy singles. A suit like this one could backfire and demolish many of the premium online dating sites.

Companies like Match, eHarmony, and Yahoo! (NASDAQ:YHOO) rely on serial daters to keep their premium services going. If all these lengthy registration forms are bunk, why should folks looking for love bother with the tollbooth-anchored dating sites?

It's free to post an ad on Craigslist to reach others within your town. PlentyOfFish.com is another free website that claims responsibility for 500,000 relationships last year alone. Don't forget the folks who are hooking up on free social networking sites like Facebook, News Corp.'s (NYSE:NWS) MySpace, and United Online's (NASDAQ:UNTD) Classmates.

Why would eHarmony rock a boat that is already taking on plenty of water from free matchmaking sites out there? I just don't see why eHarmony rejects a premium-paying model.

Stupid cupid. It shot itself with its own arrow.

Yahoo! is a Stock Advisor recommendation. To check it out without risking a dime, go for a free, 30-day trial subscription.  

Longtime Fool contributor Rick Munarriz has been happily married for 17 years; he's even forgotten how to flirt. He does not own shares in any of the stocks in this story. Rick is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a cute disclosure policy.