Unless you're one of the two men Martha Stewart has chosen as finalists for her Match.com date, you probably think your chance to cash in on online dating is gone. In the attached clip, Whitney Tilson author of The Art of Value Investing, says there's a more conventional strategy most people miss.

While Match.com is already owned by Barry Diller's IAC/InterActiveCorp (IACI), Tilson says he's taken a shine to online personal website operator Spark Networks (LOV), stressing that the stock is only appropriate for those "with an appetite for something very small."

Spark is the company behind JDate.com, by far the dominant player in the niche of setting up Jewish couples. As the dominant brand in a slow-growth space, Spark was kicking off cash with JDate but struggling for growth. To address that happy problem, Spark decided to expand in the most logical way possible.

"About three years ago they decided to go after the much bigger market of Christians in this country, which is about 30 times the size of the Jewish market," Tilson explains. Using profits from JDate, Spark started ChristianMingle.com. "Christian Mingle, in just three years, is now bigger than JDate and growing like a weed."

More than a few caveats apply. Spark's market cap is about $170 million and shares are relatively illiquid. It's always the case that investors need to do their own homework on stock ideas. In the case of small caps, that's especially true. Tilson freely discloses that he has a large position.

Those points having been made, there's also the problem of coming up with an appropriate valuation. "They don't have any profits because they're taking all the profits and reinvesting into a growth vehicle," Tilson concedes. But that doesn't mean there's not a compelling growth story.

Spark has sites dedicated to military singles, Mormon singles, deaf singles and almost any other vertical you can think of. Although, for the moment, JDate and Christian Mingle account for more than 90% of the company's revenues.

Tilson thinks JDate alone is worth as much as the entire market capitalization of Spark. Should the company achieve anything even close to the penetration they've had with JDate in any of its other divisions, the rewards could be vast for patient shareholders.

In a risk/reward sense, that makes Spark a lot like online dating itself.