A few weeks ago, the research and analytics firm Hitwise (part of Experian) made headlines by announcing that Facebook had trumped Google as the most visited web site in the US with a slightly over 7 % share of all web hits.

While this announcement (and the methodology behind it in particular) has caused quite a bit of debate, we believe this is still very significant news.

When you combine this milestone with the stellar growth of mobile Facebook usage (it quintupled from 20 million active users in January 2009 to over 100 million users in January 2010), we definitely have something to think about.

Why we think this matters

We think it is fair to say Facebook is really the first smart phone killer app for the masses. We have actually heard people ask how well one can use Facebook on a particular phone instead of speaking about the mobile browsing experience. A case in point was a Las Vegas cab driver on a recent trip who was cursing his Blackberry because it had a bad Facebook experience.

When 100+ Million people start doing this, it will have a profound effect on what is expected of mobile phones. Facebook is no longer just a web site, it is actually starting to define the user experience of the mobile Internet or perhaps even smart phones and feature phones to a degree. This, in turn, will have a direct effect on what kind of phones people want and buy.

Facebook is also the application that teaches the great masses to grab a phone not only to call or text but also to see what is going on. This should be good new for other mobile apps as they can move ahead on this path blazed by Facebook.