Investing in exciting but unproven companies can be frustrating -- especially during a recession. But the long-range rewards are worth all the short-term pain.

Longtime Motley Fool Rule Breakers pick Universal Display (NASDAQ:PANL) is no exception to that rule. The organic light-emitting diode (OLED) technology specialist didn't impress with its first-quarter report, as revenue improved by 4% over last year to $2.83 million, but net losses expanded from $0.12 to $0.15 per share.

The company sports operating expenses that are about three times as large as the incoming sales. Universal Display is banking on an exponential growth curve once OLED devices truly make it into the mainstream, and is scaling its infrastructure according to the demands of sudden, massive growth. That just hasn't happened yet -- but we're getting there.

In a field that has stayed in the Real Soon Now(tm) category for years, it's exciting to see that several of Universal Display's licensees and partners are finally bringing real OLED-based products to the shelves of Best Buy (NYSE:BBY) and electronic aisles of Amazon (NASDAQ:AMZN). Not only that, but they often market these gadgets with the benefits of OLED displays front and center.

The Samsung Impression cell phone, for example, is available through AT&T (NYSE:T) today and gets glowing praise for its "absolutely gorgeous" OLED display with bright, vibrant colors in any light. Sony (NYSE:SNE) sells really expensive, really flat small-screen OLED TV sets -- but also a brand-new OLED Walkman that aims directly at Apple's (NASDAQ:AAPL) iPod Touch and iPhone markets.

According to market research firm DisplaySearch, only about $600 million worth of OLED gadgetry made its way to consumers worldwide last year. However, it also predicts that in five years the market should be about 10 times larger, fueled by larger television screens and wider acceptance in the small-screen gadget sector. Samsung has announced plans to sell serious 23-inch OLED displays in 2010, and Sony and LG Philips Display (NYSE:LPL) aren't far behind.

So Universal Display is still frustrating to us shareholders, but that frustration will turn into monetary rewards in the next year or so -- and much larger rewards in the years after that initial burst. Did you know that OLED could replace every light bulb in the world for power savings and much longer replacement cycles?

Yeah. Huge growth opportunities await. They're just hard to see in Universal Display's financial reports these days.

Further Foolishness:

Universal Display is a Motley Fool Rule Breakers selection. Apple, Amazon, and Best Buy are Motley Fool Stock Advisor picks. Wal-Mart Stores is a Motley Fool Inside Value selections. The Fool owns shares of Best Buy. Try any of our Foolish newsletters today, free for 30 days.

Fool contributor Anders Bylund owns shares in Universal Display, but he holds no other position in any of the companies discussed here. You can check out Anders' holdings or a concise bio if you like, and The Motley Fool is investors writing for investors.