• by Gavin O'Malley  @mp_gavin, October 20, 2015

While social marketing has reached a saturation point, shifting tastes are benefiting some networks more than others.

The biggest winner continues to be Instagram -- and, by extension, parent company Facebook -- according to the latest findings from eMarketer.

This year, 32.3% of U.S. companies with 100 employees or more will use Instagram for marketing activities, the researcher calculates.

That number will jump to 48.8% in 2016, and, by 2017, increase to 70.7% of U.S. companies, eMarketer predicts. Instagram will then overtake Twitter for the first time in terms of popularity among marketers, if the forecast holds out.

Debra Aho Williamson, a principal analyst at eMarketer, said the rise of Instagram is a natural one.

“Now that Instagram is opening up advertising to all businesses, it's not surprising that marketer usage will grow rapidly," Williamson said in the new report. “Its close ties to Facebook are a key advantage.”

As Instagram attracts marketers new to the platform, marketer usage of Twitter is plateauing, according to Williamson.

The number of U.S. companies using Twitter for marketing purposes will continue to grow, but penetration will increase by just 1.4 percentage points between this year and 2017.

Facebook is similarly saturated among marketers. In 2015, eMarketer expects 84.7% of US companies with 100 employees or more to use Facebook for marketing activities. That share should rise only marginally to 85.3% in 2016, and 85.8% in 2017.

Overall, 88.2% of US companies presently uses at least one of the major platforms.