First, there was Yahoo! (NASDAQ:YHOO). Then there was Google (NASDAQ:GOOG). Is it Cuil's turn to take the throne in the search-engine kingdom?

The correct answer is "probably not," but there's too much at stake to write off Cuil completely.

For starters, there's a little Google pedigree in Cuil (which, contrary to instinct, is pronounced "cool" instead of "quill"). Google acquired the technology behind Anna Patterson's last search engine four years ago. She spent two years at Google after that before leaving the company, gradually constructing Cuil along with a few former Google engineers.

The site claims to scour far more of the Web than Google does. It promises to sift through more than 120 billion pages to arrive at the best results. Google no longer publicly offers up its breadth, though its silence there will only stir up the hype that Cuil is, in fact, the new Google.

But for Cuil, search-engine supremacy isn't a matter of breadth, or even depth. Google has a well-known brand, existing search relationships with the likes of Time Warner's (NYSE:TWX) AOL and News Corp.'s (NYSE:NWS) MySpace, and an army of installed toolbars and Google AdSense spots on countless third-party sites.

Cuil may or may not offer superior searching. A few sample searches on both engines found Google delivering more results, though the actual quality of those results will always be subjective.

The key is that Google can't ignore an attack from engineers it once found hire-worthy, much less the mastermind behind a technology it once found worth buying.

Fade to black
Cuil is different. You feel it the moment you load the site. Instead of the standard white background you find on Google, Yahoo!, and the inner frame of Microsoft's (NASDAQ:MSFT) Live Search, Cuil's backing is pitch black, as in Spinal Tap Smell the Glove "none more black" black. Unlike the growing number of options you find on established portals, all Cuil offers is the logo search box, above links to the site's privacy statement and about page.

The info page details the origin of the name -- Gaelic for "knowledge," supposedly -- and feature's Cuil's claim to have indexed three times as many pages as Google, and 10 times as many pages as Microsoft. Again, this won't be the lone barometer of success, but it certainly will help Cuil win media coverage and tire-kicking interest.

Search results are also delivered in a unique way. Since the website currently features no sponsored ads, Cuil can offer up results in several columns. If you thought IAC's (NASDAQ:IACI) Ask.com brought something new to the table when it introduced landing-page thumbnails, Cuil rearranges the entire tabletop.

Where will Cuil be in a year?
Cuil's launch and media blitz will keep the site busy over the next few days. The strength of the management team -- down to the founding CTO of 1990s search stalwart AltaVista -- warrant as much. The key will be to get visitors to bookmark the site, or ideally make it their new home page.

The even bigger challenge down the road lies in how Cuil will be monetized. It doesn't have to be, of course. Sites like Wikipedia and Craigslist have probably thrived as a result of their ad-repelling ways. However, Google commands a $150 billion market cap, with 99% of its revenue coming from online advertising. It's hard to believe that Cuil will pass up such a chance, should it grow popular enough to cash in via the lucrative paid-search market.

The bigger question is whether it will even get that far. If Cuil gains momentum over the next few months, do you really think that Microsoft or Yahoo! will sit back and let someone else eat further into their dwindling market-share slices? The most likely scenario is that a rising Cuil becomes buyout fodder, with Microsoft outbidding Yahoo! to snuff out a threat and gain more ammunition against Google.   

The other scenario is that Cuil will fade, just as once-budding search stars such as AltaVista, Lycos, and LookSmart (NASDAQ:LOOK) also fell from temporary grace. AltaVista and Lycos were right up there with Yahoo! in the late 1990s. LookSmart once powered Microsoft's paid-search efforts.

I happen to like Cuil's chances, though. Its timing couldn't be better, at a time when Web users are gun-shy over how search engines are keeping and manipulating search history data. If Cuil becomes the new "do no evil" player, it could be a feel-good winner.

Watch your back, Google -- no matter how far away the items in the rearview mirror appear to be.

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Longtime Fool contributor Rick Munarriz is always searching for search solutions. He does not own shares in any of the stocks in this story. He is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.