Instagram has apparently passed Twitter for the most daily mobile users in the US for the first time, according to a report from AllThingsD which cites a “comScore mobile audience measurement report that has not been made public.”

The report seen by AllThingsD reportedly claims that, for the month of August, Instagram saw an average of 7.3 million DAUs (daily active users) accessing the service via smartphones. The report pegs Twitter’s DAUs for the same group at 6.868 million.

The report apparently also states that the average Instagram user was present on the service for 257 minutes during August compared to Twitter’s 170 minute average.

The data suggests that Instagram has, in spite of the fact that the photo-sharing service has some 7 million fewer mobile users that Twitter does in the States (around 22 million compared to around 29 million), managed to outpace the growth of Twitter in a remarkable span of time.

As Facebook, which is now Instagram’s parent company, is trying to move more aggressively into the mobile space Instagram’s performance could give it the foothold it needs to compete with Twitter in the mobile sphere. Facebook and Instagram – despite the positive numbers which will need to be sustained – still face the challenge of turning the mobile photo-sharing experience, as well as Facebook’s own mobile offering, into a tangible revenue stream, something that Twitter already seems to have locked up with their existing mobile ad service.

Source: AllThingsD