Instagram has overtaken Twitter in daily mobile users. According to comScore, the image sharing site now has 7.3 million daily active users, compared to Twitter's 6.9 million. Smartphone owners also spent far more time on Instagram — an average of 250 minutes to Twitter's 147. Since Instagram has only 22 million US users to Twitter's 29 million, this is quite a healthy engagement level. The change is sparked byRead more