One of the most important lessons for an investor, Cramer said Thursday, is understanding what could move the needle for a stock.

The "Mad Money" host came to the topic after recently taking a question from a viewer. Kent in Wisconsin wondered whether MiO, a new concentrated line of liquid flavorings from Kraft Foods , could give the packaged food company's stock a bump. Before addressing Kraft specifically, Cramer spoke about what moves the needle in general.

Most new products won't move the needle for a company's stock, he said. There are, however, some rare cases where a new product will make a difference. If a company is very small, for example, a new product might be enough to make a splash. Hansen Natural was a tiny, speculative company when it launched Monster Energy drinks in 2002. Since then, its stock has soared and the company now gets 90 percent of its sales and profits from the rapidly-growing, $27.3 billion alternative beverage category.

If a new product completely changes the nature of the company, that could also bump the stock. Wynn Resorts and Las Vegas Sands , for example, experienced this when they decided to open casinos and resorts in Macau. Since then, both companies have focused less on Las Vegas and more on the "Las Vegas of China."

With this criteria in mind, Cramer doesn't think Kraft's MiO will move the needle. After all, Kraft is a huge packaged food company and innovating new products is simply part of their business model, he argued.

"There's nothing game-changing about it," Cramer said of Kraft's new product. "Kraft constantly needs to innovate and expand in order to fend off the competition and maintain their slow but steady growth rate."

In 2010, 9 percent of Kraft's sales came from products it introduced within the past three years, Cramer said. Kraft hopes to introduce this number to 11 percent by 2013 by increasing spending on research and development. It's a $60 billion company, though. So no matter how successful MiO is, Cramer doesn't think it's going to be enough to move the needle, especially when it's patent-pending. Cramer said Kraft needs these kinds of successful products just to hit its growth targets and support its valuation.

What's the bottom line?

"When you see news of new products from a company, be sure you understand that the vast majority of these stories are not big enough to move the needle," Cramer said.

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