Twitter Traffic Down -9.63% For February, Facebook -4.32%, LinkedIn -8.30%, Friendfeed +71.79%

This is a monthly series that looks at visitor data for all the major social networks as calculated by Compete is USA-biased, and certainly in the case of Twitter the visitor numbers are distorted by the openness of Twitter’s API and the numerous Twitter software clients, but on a like-for-like basis the numerics have value and warrant investigation. Please refer to previous installments in this series for a more detailed overview.

Twitter traffic fell an eye-opening -9.63% in February, registering 21,303,254 unique visitors, and 143,947,420 overall (-5.01%).

Even accounting for a growing use in Twitter clients (which do not register at Compete), and February being a shorter month, that’s a pretty worrying statistic for Evan Williams et al, especially as they prepare their much-hyped advertising platform.

Facebook and LinkedIn also fell sizeably, down -4.32% and -8.30% respectively. Overall visits at Facebook dipped -2.51% to just over 2.8 billion.

MySpace took the biggest hit, losing -11.52% of unique visitors.

Elsewhere, Friendfeed rallied an impressive +71.79%, registering 858,703 uniques, its highest point since August 2009.

Assuming these figures are accurate (and remembering that they predominately reflect US data and visits to .coms), it’s a very mixed bag indeed, and possibly of concern for the larger social networking platforms. It’ll be interesting to see if February’s figures are an anomaly, and all sites bounce back in March, or whether we are witnessing the beginning of a more significant downtrend across all of social media.