The engine, unveiled today, boasts it indexes 120 billion pages -- or three times Google's 40 billion. But these raw numbers aren't all that useful when determining whether a search engine can return pages related to users' queries. Index size also isn't an especially reliable metric, because different companies sometimes use different tallying methods.
Regardless, Cuil certainly isn't the first would-be Google rival. The search giant's success has spawned a host of entrants into search, but none have come close to putting a dent in Google's commanding market share.
Cuil also had some crashes this morning, but that's not necessarily a bad sign; sites often need to get some bugs ironed out when they launch.
In some ways, what's most notable about Cuil is that the company is touting itself as privacy-friendly. The home page contains just two links -- "About Cuil" and "Your Privacy." Users who click on the privacy link land on a page that states, "We do not collect any personally identifiable information, period. We have no idea who sends queries: not by name, not by IP address, and not by cookies." Cuil also states it doesn't store logs of users' activity on the site.
If nothing else, Cuil's move shows that privacy considerations are top of mind in Silicon Valley these days. Companies might disagree about the wisdom of storing IP addresses, but there's no real question that query logs can reveal users' identities, as the world learned two years ago AOL released three months' worth of query data for 650,000 anonymized users. One such user, Thelma Arnold, was identified in a matter of days by The New York Times.
Google insists that it needs to store query logs to improve its search results and to guard against click fraud. But the emergence of companies like Cuil calls into question whether Google needs this information as much as it says it does.