According to Compete.com, traffic to Facebook declined under 1 percent within the United States for the first time in over a year after posting less than stellar growth the month prior. Given that the traffic estimates were only domestic, summer vacations may have been the cause for the lack of growth. Twitter in contrast posted minor growth of 1.27 percent. Also fairly strange was a dramatic drop off in traffic to Facebook Connect enabled sites.

Compete’s measure of traffic to websites only accounts for domestic traffic and given that most other sites didn’t post much of a gain or loss over the past couple months, suggests that this was an overall traffic trend, not limited to Facebook. Alexa and Hitwise numbers show that Facebook is continuing to grow at impressive rates at the expense of once competing MySpace. So how should one interpret these numbers?

My guess is that Facebook’s global growth has continued to skyrocket. Hitwise’s recent charts also may not actually suggest that traffic has grown, instead that Facebook’s share of the social network market has continued to increase over the past few months. However overall traffic to social networking sites appeared to be relatively flat for the month of August, meaning that Hitwise’s charts actually confirm that overall growth was flat for the past month.

Reading into Facebook traffic on a month by month basis is a dangerous thing though especially with all the momentum that the company appears to have. Taking one or even two months of flat growth should make analysts cautious about upcoming growth, however I’d wait for September numbers to see how overall traffic performs. With students returning to school, I’d expect traffic to continue to grow.