Remember how cool Smart Boards looked when they first showed up? Corporations bought them in the 1990s, but a lot of people discovered them years later when they started flooding school classrooms. With a Smart Board, seven-year-olds and CEOs alike can write on a screen for all the room to see.

The inventor of the boards, SMART Technologies (Nasdaq: SMT), saw sales leap up for years before launching a successful $660 million IPO last July. But things went sour almost immediately. School budget cuts hurt sales, and increasing competition forced the company to spend more on R&D. The company expects 2011 sales to be flat to 5% lower. Shareholders have taken the brunt.

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SMART Technologies Price Stock Chart by YCharts

There's a difference between great products and great investments. High debt, competition or just management's lack of long-term planning can turn great products into truly horrid investments. Moreover, some of the best-run of the great-product companies are dogs for investors when their share prices run up too high. It's hard, even with the niftiest gadgets, to ramp up profits fast enough to meet the expectations high valuations imply. High valuations tend to lead to big falls when the news is less than super sunny: like when a new competitor makes noise; or when the sales gain for a particular quarter isn't quite as high as promised.

Here's a look at a couple of great-product companies in today's market that seem to have less-than-great potential for today's investors. They're not necessarily Smart Techs-in-the-making, but they each have weaknesses that should make investors wary. YCharts Pro gives both companies Neutral ratings.

Shutterfly (Nasdaq: SFLY) -- Most of us have opened an emailed photo with Shutterfly whether or not we've ever paid the company any money. Thousands of customers make photo books, greeting cards, calendars, stationary and pretty much anything else you'd want to do with a picture using Shutterfly. It was one of the first companies to build a user-friendly way for Joe and Jane Public to pretty-up and package their digital photos. Annual revenues grew to about $300 million. Problem is, Shutterfly hasn't figured out a way to make money in this business yet. Losses continue in the forecasts.

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Shutterfly Earnings per Share (TTM) Stock Chart by YCharts

IMAX (NYSE: IMAX) -- Everyone knows IMAX from, well, IMAX, those giant theaters that make an ordinary movie so much bigger than life. The company designs and builds extremely expensive projection systems for IMAX theaters, and it's a big producer of 3-D films. Despite a disappointing first quarter this year, the company generally has had good revenue and income growth and little debt. But its shares are trading at a P/E of over 26, and a price/sales ratio of over eight. In other words, investors are looking for more than modest leaps in sales to come.

But entertainment is an expensive business, and the trends in big screen televisions are better than those in movie ticket sales. IMAX's R&D version of the business requires cash, and this company's cash figures are going the wrong direction.

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Imax Corporation Cash Operations (TTM) Stock Chart by YCharts

While there's nothing horribly alarming about this picture, it's a good excuse to settle for a movie ticket instead of the shares.

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Dee Gill is an editor for the YCharts Pro Investor Service which includes professional stock charts, stock ratings and portfolio strategies.

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