It seems like the jockeying for position among social networks is never-ending.

The latest case in point:  Instagram, which is presently the fastest growing social media network in the United States.

According to the latest figures released by digital market research company eMarketer, as of February 2015 Instagram now has over 64 million users in America.

That’s a ~60% increase in just one year, and it puts Instagram in third place among all social networks, surpassing Twitter for the first time.

Not only that, eMarketer forecasts that Instagram will add more than 10 million additional users in the United States this year:

• Facebook: ~157 million U.S. users forecast in 2015
• LinkedIn: ~115 million
• Instagram: ~78 million
• Twitter: ~53 million
• Pinterest: ~47 million
• Tumblr: ~20 million

       (Source:  eMarketer and LinkedIn, February 2015.)

eMarketer also forecasts that Twitter will continue to fall further behind Instagram in the upcoming years, since Twitter’s annual growth is expected to be in only the single digits throughout the rest of the decade.

Based on the overall American population, Instagram has now a market penetration of nearly 25%.  Of course, that’s well behind Facebook, which has nearly 50% penetration.

But Instagram’s user base is skewed heavily towards teens and millennials – people between the ages of 12 and 34.  This makes Instagram a bit more of a threat to LinkedIn and even Facebook than you might think at first.

Facebook’s user base has been skewing older in recent years.  If those trends continue, we could see a measurable drop-off in Facebook’s share of users, with a corresponding rise in Instagram’s penetration.

Of course, we mustn’t forget that Facebook was the social media network of choice for younger people at one time, too.  After all, it got its start on college campuses.  But now that Facebook has solid adoption among older Americans (age 40 and over), no longer does it seem like a “cool” network for some millennials and teens.

So it would be foolish to assume that Instagram is a slam-dunk to continue to be the “network of choice” for younger people in the years hence.  One never knows what new network might suddenly appear on the horizon and capture their hearts.

Still, Instagram’s rise has been noteworthy.  And it certainly puts the lie to the notion that there wasn’t room for a new network to enter the increasingly crowded social media space and make a big splash.

Personally as an “aging boomer,” I don’t have an Instagram account, and neither do most of my acquaintances.  What about your own personal experience or professional experiences with this network?