Updated from 8:47 a.m. EST

The strange story of Internet search engine Mamma.com ( MAMA) got weirder Tuesday when billionaire investor Mark Cuban reported a 6.3% stake in the company via a Securities and Exchange Commission filing.

Cuban, the excitable owner of the Dallas Mavericks who laid up his grubstake by selling Broadcast.com to Yahoo! ( YHOO) in 1999, said in the filing he has 600,000 shares in the $50 million market-cap Mamma.com. He crossed the 5% threshold that requires SEC notification on March 4.

Mamma.com has bounced around like a loose ball since changing its name from Intasys in January and deciding it was no longer a provider of "global wireless Internet-compatible billing and customer care information systems," but rather "the mother of all search engines." The shares tripled to more than $15 in the space of two days early this month, trading north of 65 million shares on March 2 and 3 -- respectable volume for a company that had 6.5 million shares outstanding at the time.

Cuban, who said in the filing that his stake is passive, currently is chairman and president of HDNet, a Dallas-based provider of high-definition television programming. His track record as a value investor is sound given the appreciation in one of his holdings, Charter Communications ( CHTR), over the past year.

In a statement to TheStreet.com, Cuban said there's a lot to like about the company.

"I like companies that generate cash," he said. "This company doesn't have to be the next Google or Yahoo!. Heck, they don't even have to be a top 10 search engine. What drew me to them was a search for pictures I was doing for a project. It did a better job than the bigger engines. So I continued to use it.

"When I found out it was public, and they got rid of the non-Internet assets and did my due diligence, it had the features I look for in Internet companies. Low overhead (only 38 employees, 7,000 square feet of space, reasonable salaries), and they convert traffic to cash and let that cash fall into the bank."

"If they continue to grow their traffic, which I think they can, and they continue to convert that revenue to cash at the same percentages, which I think they can, while keeping overhead down, this will be a good investment," Cuban said.

The Mamma.com filing had a predictably self-fulfilling aspect, driving the shares up $2.12, or 27%, to $9.98 Tuesday morning.