Watch your back, Twitter.

The information network has a serious challenger in photo-sharing phenom Instagram, which won the all-important race for mobile attention and engagement in August.

Instagram users cumulatively spent more than 5.65 billion minutes using the service on mobile in August, according to data collected by analytics firm comScore. comScore’s data is specific to U.S. smartphone owners ages 18 and older running iOS, Android, or RIM operating systems.

The photo-sharing sensation, which has more than 100 million users, drew nearly 22 million unique visitors on mobile that month, and 7.3 million total mobile users per day. In August, the average mobile Instagram user spent 257 minutes, or 4.283 hours, with the service.

Twitter, however, attracted 29 million unique mobile visitors in August, or 7 million more than Instagram, but saw less daily attention and overall engagement. Information network consumers in the U.S. posted a total of 4.9 billion minutes, which amounted to about 170 minutes per visitor, on average. Twitter also saw 434,000 fewer daily mobile users than Instagram on average, according to comScore’s calculations.

The data explains why Twitter was initially taken with Instagram, and underscores why Facebook was keen to snatch the mobile service away from its 140-character competitor.

While Twitter and Instagram seemingly have little in common — one service is for posting quick bursts of information, the other for sharing photos — the two now compete for breaking news and celebrity attention. It’s a battle that has already come to blows.

Data provided to VentureBeat by comScore; via AllThingsD

Photo credit: maaco/Flickr

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