Photo-sharing site Instagram, the hottest new social hub for brands and the fastest growing network in terms of new users and frequent use, has experienced a significant drop in user interaction during the last 12 months, according to a new study by San Francisco-based media analytics company Quintly.

While experiencing a marked increase of use by brands in 2015 that continued into the early months of this year, Quintly’s study reveals an overall user interaction decrease of 33 percent from the same period a year ago. This figure includes an average 27 percent decrease in image interactions and a 39 percent decrease in video interactions compared to 2015’s first quarter.

Declines particularly hit profiles with the highest number of followers: profiles that hold between 100,000 and one million followers saw a 36 percent decrease in image interactions, and profiles with at least 10 million followers experienced a 39 percent drop in image interaction. The phenomenon was even worse for video: profiles with between one million and 10 million followers saw interactions plummet by 54 percent, and profiles with more than 10 million followers experienced a 62 percent decrease in user interaction.

There are a few silver linings. Profiles with the smallest number of followers — fewer than 1,000 — saw image and video interaction decreases that were, essentially, negligible. Moreover, Instagram’s overall share of video posts on timelines has surged by 10 percent, from five percent during 2015's first quarter to more than 15 percent today.

Facebook meanwhile, which should be suffering from saturation after 10 years, still outpaced Instagram for post increases during the first quarter of 2016, and that site’s users still post more frequently each day than Instagram users.

Quintly in May reported that while Instagram had exhibited the greatest surge in new follower gains and overall user interaction rates, number-one social site Facebook still experienced almost constant growth and daily post activity increases by greater numbers.