Facebook Grew Twice As Fast As Twitter In July

If it wasn’t bad enough that Facebook bought FriendFeed on Monday and turned on real-time search to better compete against Twitter in the Stream Wars, and is playing around with a lite version that resembles Twitter even more, now Twitter really has something to worry about. Facebook is growing faster than Twitter in the U.S., even though it is more than four times larger.

In the month of July, according to the latest estimates from comScore, Facebook attracted 87.7 million unique visitors in the U.S., which was 14 percent higher than in June, 2009. Twitter, in contrast, only saw 21.2 million unique U.S. visitors to its Website, a 6 percent rise compared to the month before. In absolute terms, Facebook added about ten million new visitors in the month of July versus roughly one million new visitors for Twitter.

At 87.7 million uniques, Facebook moves from the sixth largest Web media property in the U.S. to the fifth, passing the combined sites of Fox Interactive Media (80.9 million uniques) and coming within striking range of AOL (104.8 million). That is just in the U.S. Facebook is already the fourth largest site in the world (and Twitter is doing better worldwide as well, with a total of 44.5 million unique visitors in June).

Note that these estimates are only for Twitter.com and do not include mobile or desktop clients such as Tweetdeck, Seesmic, or Tweetie, but it should be a good proxy for overall growth. Even if you double the numbers for Twitter, Facebook still trounced it in July (and the Facebook numbers don’t include activity on other sites other apps via Facebook Connect either).

These are month-over-month comparisons. On an annual basis, Twitter is still growing its audience much faster (2,614 percent ) than Facebook (124 percent) because it is coming off such a smaller initial base of users and this was the year it entered hypergrowth. But that hypergrowth seems to have slowed since the end of April, at least in the U.S. Between April and July, Facebook grew 30 percent in unique U.S. visitors, while Twitter only grew 25 percent, so it is more than just a one-month aberration.

So what happened in June to accelerate Facebook’s growth? I don’t think it was the vanity URLs. Rather, on June 24, Facebook turned on the “Everyone Button.” Facebook members who didn’t have public profiles (i.e. most people) all of a sudden had the option to share items in their stream with everyone else on Facebook, and they could decide to do this on an item-by-item basis.

The more items that are shared publicly, the more people who can see them. I believe this is what happened (and have asked Facebook for confirmation). Not only did this drive more people to Facebook, but it also increased the time spent on the site by a whopping 36 percent in June versus July. Twitter saw its time on site grow 26 percent in the same period, although in the chart comparing the two below you can hardly tell because Facebook users spent an estimated total of 15.8 billion minutes compared to 4.75 million minutes for Twitter. What that tells me is that the stream becomes more engaging the more public it becomes.