According to recently released comScore data so successful is Instagram that in August US smartphone users visited the photo app more frequently, and for longer periods of time, than they visited Twitter.

The report says that in August, Instagram had an average of 7.3 million daily active users compared to Twitter’s 6.9 million.

A report on AllThingsD it says that Instagram user spent 257 minutes accessing the photo-sharing site on their mobiles while the average Twitter spent 170 minutes viewing the site.

What’s further interesting here is that Twitter has far and way more users. It racked up around 29 million unique US smartphone visitors in August compared to the 22 million that Instagram chalked up.

Thinking about how we use those two apps it is not entirely surprising. People spend a great deal of time taking, editing and playing with their pics. That accounts for all that time.  While on Twitter, I would say, we tend to dip in and out and for shorter periods of time.

AllThingsD says it is a big deal for a number of reasons:

That the barely-two-year-old Instagram could rocket up in user engagement and retention in such a short amount of time, eventually surpassing Twitter in the process, speaks to the sheer momentum of the photo-sharing product.

 

Above all else, it speaks to the ongoing mobile issues of Facebook, now the parent company of Instagram. The massive shift in user traffic to mobile devices is a real thing, and Facebook seems to now hold an asset in the highly popular Instagram. The trick now, however, is to figure out a way to effectively monetize Instagram and the Facebook mobile experience.

Twitter, with its own ad product suite of promoted and paid tweets, seems to have cracked this. The company trumpets its ad business as already lucrative in the two years since its inception, though it has not provided any hard revenue projections to back this up. Current eMarketer projections for Twitter’s 2012 mobile ad revenue, however, put the start-up’s ad products near the top of the heap; eMarketer projects that Twitter will rake in close to$130 million in mobile ad revenue in 2012, nearly doubling that of projections for Facebook, which sit at around $72 million, AllThingsD  reports.

Mobile is obviously huge for everyone and Twitter is finding a great deal of success on it. Not only in terms of users, but increasingly it is making more money and getting higher engagement levels via mobile as we wrote about yesterday.

Why is that? Pretty simply as we wrote in July:  Twitter users are more likely to access the social network with a smartphone than users of any other social site…except we can now add to that Instagram.

This presents a great opportunity for Facebook. Its challenge is to find someway to make cash out of Instagram (and mobile more generally) and do that in a way that doesn’t ruin the experience of Instagram or scare away the users. Facebook did, after all, pay $1 bn for the photo sharing site.