The world of information retrieval has gone through some drastic changes over the past decade. With an overwhelming amount of information available in cyberspace, and more gigabits being added daily, finding what you're looking for online will become increasingly difficult. As time goes by, search engines will become even more essential for exploring the Internet.

Google (NASDAQ:GOOG) has become synonymous with Web searches, and it has the numbers to back up its apparent ubiquity. For April 2006, comScore Networks reported that 43.1% of all U.S. searches used Google, and its dominance in the worldwide market is even greater.

Its popularity may stem partly from the PageRank algorithm Google uses to produce better results. But for those of you bearing anecdotal evidence that Google's search tools are no better than those from Yahoo! (NASDAQ:YHOO), Microsoft (NASDAQ:MSFT), AOL, or IAC/InterActiveCorp's (NASDAQ:IACI), I'd argue that several subtle differences make Google a more appealing choice in users' subconscious minds.

The biggest and most important difference is its simplicity. The main Web page is a logo, one text box, two buttons, and about 10 or so uninvasive links. What other $100 billion (or even $1 billion) company has always had a home page like that? Apple (NASDAQ:AAPL) takes a similar approach in its product packaging. A box with a couple pictures and a few words? Whatever's inside must be pretty easy to use! That's in direct contrast to Microsoft offerings (which is why this video of how Microsoft might redesign the Apple iPod packaging is so funny).

When you only have a few seconds to make a first impression, you must quickly give your audience a reason to stick around and try your product. Others have copied the design of the main search page, but Google has mastered this art by studying its audience and fine-tuning all of its pages to the user experience. Ironically, the better Google is at providing its main service to customers, the less time they will spend on its website. Of course, since many users' destinations contain Google advertisements, it's often a win-win situation.

Speaking of advertising, Google raked in more than $6 billion last year by selling advertising space -- which is essentially 100% of its revenues. This tends to be one of analysts' biggest gripes with the company: They mark it as a one-trick pony. I find that rather absurd, since I would only reserve that kind of label for niche companies, and Google's anything but. Web advertising may be its only source of revenues right now, but it has positioned itself to benefit from all forms of media advertising. Can you name another company that will most likely command a significant portion of the handheld-device advertising market?

It's perhaps most amazing that Google remains flexible, even as it becomes ubiquitous on the Web. It has stayed focused on its mission to organize the world's information, making it universally accessible and useful. Is it a bit idealistic? Maybe. But so far, it's been a perfect plan, because it can take a large role in the next sweeping change to the Internet, whatever that may be. Video? Covered. Podcasts? Mobile search? VoIP technologies? Yep, yep, and yep.

Its position has become so enviable that many of the giants of Internet commerce, including Microsoft, Yahoo!, and even eBay (NASDAQ:EBAY), are starting to sweat. In fact, it was even reported that these three highly competitive companies were considering a joint effort to keep Big Goo at bay. There's good reason to be afraid, because Google is doing a better job of giving its users what they want. To me, this is capitalism at its best. Fear of a competitor's products, instead of its legal team, is a powerful motivator for innovation. Consumers will benefit greatly -- as long as the fight remains out of the courthouse.

So far, I've done my best to avoid what is likely the toughest aspect of Google to defend: its high valuation. As I've previously argued, even without considering the other potential areas for growth, it's possible that advertising alone could support Google's current valuation. If we add in a conservative view of all the other pieces of the Google puzzle and what revenues might be produced, I believe adding Google to a well-diversified portfolio will very likely produce pleasing results over the next 10 years and beyond.

Think you're done with the Duel? You're not! Go back and read the other three arguments, and then vote for a winner.

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Fool contributor John Bluis does not own shares of any company mentioned in this article. The Motley Fool is investors writing for investors.