This month marks the launch of Motley Fool Hidden Gems, my newsletter service designed to dig out, evaluate, price, and recommend the greatest unknown companies and stocks in America.

Every amazing stock in America was, at some point, a relative unknown. In fact, two of the greatest businesses and greatest stocks of all-time -- stocks that turned thousands of dollars into many millions of dollars -- were completely disregarded (if not laughed at) by Wall Street and Main Street in their early years.

Sam Walton's Wal-Mart(NYSE: WMT) was nothing more than a cute country store run by Arkansas bumpkins that Kmart would devour en route to dominating the national scene for superstores. Or so they said. For years as a public company, Wal-Mart toiled profitably in obscurity. Today, it's a $230 billion company.

And what about Rollin King and Herb Kelleher's Southwest Airlines(NYSE: LUV)? That business was formed out of the acquisition of a Texas outfit named the Wild Goose Flying Service, and it took three years of legal battling with Continental Airlines and Braniff to get their first plane in the air. Funny, isn't it -- there haven't been many better-performing stocks in America over the last 30 years than Southwest Airlines.

These kinds of stocks just kept doubling and doubling and doubling again. Investors who found them early on made fortunes.

In Hidden Gems, I'm going to lead a fanatical search to find the greatest of these underfollowed and undervalued businesses in America today.

I think I'm up to the task. Over the past 15 months, I've generated 25% returns through a tough market in our monthly Motley Fool Stock Advisor newsletter, which many of you subscribe to. It's been a rewarding time for all of us. I've done so by mixing in a few unknowns with larger, well-known ventures like Moody's(NYSE: MCO), Whole Foods(Nasdaq: WFMI), and Costco(Nasdaq: COST). I'll be continuing my work in this newsletter.

But now, in Hidden Gems, I'm going to focus all of my attention on the smaller businesses that have not yet caught Wall Street or the general public's eye. Each month, I'll recommend the most compelling stock of a business that:
             a) is valued under $2 billion
             b) is not yet a household name

I'll also welcome a visiting analyst -- this month, it's Jeff Fischer -- to unearth their favorite unknown stock treasure. We'll outline the opportunities and risks of every recommendation. We'll value their assets and their free cash flow. We'll provide regular updates on every selection. And we'll track all of our recommendations against the market's average return.

You'll never be in the dark.

But Hidden Gems will offer even more than that. It's going to be unlike any newsletter ever offered because we're then going to work together as a team online. Each issue will be mailed out to Hidden Gem members (in print and digitally), complete with our recommendations and our full watch list. Then we'll come together in an exclusive, private online forum to debate the merits of every stock considered.

As a community focused on underfollowed and undervalued companies -- like Foolish 8 companies and remarkable cash-generating turnarounds -- we'll be able to learn more, discover more, and profit more than any of us could have done on our own. And we're going to have a darned good time in the process.

Give it a whirl on me. The first month is free. If you don't absolutely love it, you have my personal guarantee you won't be billed or bothered.

Take a No-Obligation, 30-Day Free Trial

Tom Gardner co-founded The Motley Fool and is the executive editor of Motley Fool Hidden Gems. The Fool is investors writing for investors.