Just a few days after General Motors (NYSE: GM) broke the news that it was ending its endorsement deal with Tiger Woods, NBA phenom LeBron James' agent told reporters that Microsoft (NASDAQ: MSFT) would not be renewing its two-year old marketing deal with the Cleveland Cavaliers forward.

King James, as he is known, appeared in commercials for the Windows Vista operating system, but very little else came of the partnership. According to The Associated Press, "The partnership faltered when Microsoft executive Joanne Bradford, who struck the deal with James, resigned as head of the company's media network this year."

These celebrity endorsement deals attract little attention from investors when times are good, but with most companies faltering now, they seem to be attracting more ire. James' seven-year, $90 million deal with Nike (NYSE: NKE) makes sense: LeBron James is a powerful force in selling basketball shoes. The terms of the Microsoft deal were not disclosed, but it seems unlikely that James contributed to any increase in sales of Microsoft products -- would anyone choose their operating system based on a basketball player in a commercial?

I can't help but question the motives behind these kinds of endorsement deals: are they inspired by a desire to drive sales and create shareholder value or a desire to hobnob with celebrities?

A few months back, I wrote, with some scorn, about Brad Duke, an Idaho aerobics instructor who won $125 million and now thinks he can parlay that into $1 billion in 12 years. Duke, who insists he won the lottery because of an elaborate mathematical strategy he developed (for those who are interested, I have Enron shares for sale), is extremely unlikely to end up a billionaire. I would say that there's a good chance he'll give up a good chunk of his lottery payout.

Now comes Lebron James, the 6'8" Cleveland Cavaliers star, saying that he wants to be the first billionaire athlete (although his agent qualified that by saying that that amount would include the value of brands associated with his name that he does not own directly). Lebron just might have a shot. He signed a $90 million endorsement deal with Nike right after he was drafted out of high school, and has numerous other deals. He agreed to an $80 million extension with the Cavs last summer and, best of all, he has a great business hero: Warren Buffett. Last September, Lebron traveled to Omaha to dine with Buffett and the two have become fast friends.

Since then he bought a stake in Cannondale, a privately held line of high-end bicycles, and he also made a number of investments in start-ups and, of course, real estate.

So, does Lebron have a chance? I'd say he has an excellent chance. His willingness and desire to learn from the best, combined with the drive and determination that he's exhibited on the basketball court, are two of the most important characteristics of successful entrepreneurs and investors.

At the very least, I will bet that Lebron ends up a lot richer than Brad Duke.

If mere athletic talent sold product, kids would be lining up for Tim Duncan's shoes, since he is the best player in the NBA. But it doesn't. It takes a combination of extraordinary athletic accomplishment and charisma to push a brand over the top. Three such athletes, Amanda Beard, LeBron James and Tiger Woods, are front and center in this week's news.

Two are at the peak of their pulling power. LeBron James (Nike, NYSE: NKE, Coca-Cola's (NYSE: KO) Powerade) fresh from an astonishing game five of the NBA Eastern conference playoffs, is dominating the sports page, if not the San Antonio Spurs. The Cleveland franchise has gained $185 million in value since his signing, and the $90 million he received from Nike seems like a bargain now. When his contract expires in 2008, he could demand -- $250 million? $500 million? It is possible, by the end of the career, he could be the first $1 billion athlete?

If Tiger doesn't beat him to it. Beginning tomorrow, Tiger Woods (Nike, Buick, General Motors, NYSE:GM) starts his pursuit of the 2007 U.S. Open. He's inked a 5-year, $40 million deal with Nike, and $25 million from Buick. Unlike LeBron, Tiger can look forward to another 30 years of playing, with lots of green jackets and green cash to come.

Nike Inc. (NYSE:NKE) reported better-than-expected third quarter results and investors couldn't have cared less.

Net income was $350.8 million, or $1.37 a share, versus $325.8 million, or $1.24 a share, a year earlier. period. Revenue rose to $3.93 billion from $3.61 billion. Analysts surveyed by Thomson Financial expected on average profit of $1.33 a share on revenue of $3.92 billion.

Shares of Nike, which are up more than 25 percent over the past year, barely moved in after-hours trading. They last traded at $110.65, up less than 2 percent.

Why did investors shrug their shoulders?

Perhaps they wondered whether or not consumers worried about their paychecks are going to be shelling out $175 for the Air Force 25 or the iPod-compatible shoes that lifted Nike's profit in the quarter.

Come to think of it, consumers also probably aren't going to be too keen on other trendy shoes like Crocs Inc. (NASDAQ:CROX) and those awful wheeled shoes that kids in every mall wear made by Heely's (NASDAQ:HLYS).

We are in the dawning of the age of Payless ShoeSource Inc. (NYSE:PSS).

This weekend's Financial Times features an interview with Miami Heat star Shaquille O'Neal about his business interests, which include real estate, cash washes, health clubs and, of course, his numerous endorsement deals. His net worth is estimated by Forbes at $250 million, but he shows no signs of slowing down.

His interest in real estate development has led to a friendship with Donald Trump, who joked to Shaq, "'Dammit, Shaq! We're friends, but now we're competitors!" after O'Neal began investing in Miami real estate development.

Another, much younger NBA star, Lebron James, also has an eye for business. Last year, he had lunch with Warren Buffett, whom he considers to be his hero in the business world.

My bet: If Shaq idolizes Trump and Lebron idolizes Buffett, Lebron will become a lot richer. Shaq will probably just become an arrogant blowhard. Oh wait...