In a sunny office in the SoHo neighborhood of Manhattan, Mike Schmidt spends his time ferreting out fake Instagram accounts. Some are obvious, like the one that had never posted a photo and lacked a profile picture yet followed about 7,500 accounts — the maximum allowed by the social media site. Others are trickier. Mr. Schmidt had to scroll down a little on an account with the name @ailebnoblk before the same stock image of a car showed up three times in a row, a clue that there was no real person behind the profile. “The amount of bot activity that’s happening on these platforms is pretty insane,” Mr. Schmidt said. “Just the amount of new accounts and times these folks are liking and commenting with spam and positive comments and happy-face emojis.” Dovetale, a four-person software company Mr. Schmidt co-founded in 2016, has devised a range of tactics to identify large numbers of fake accounts that follow popular Instagram personalities. It then packages that information for marketers, who are increasingly skeptical of the audience numbers that often determine how much money social media stars can command from advertisers. Marketers are flocking to businesses like Dovetale, prompted by revelations like those in a recent investigation by The New York Times that detailed the booming industry of people buying fake followers and fraudulent engagement on Twitter and other social media sites. Some of these fake accounts, in an attempt to seem legitimate, use personal information from real people without their knowledge. That has provoked concern among brands and their agencies, which often rely on metrics like the number of followers an account has when hiring people on YouTube and Instagram to promote their products. These social media stars can often fetch thousands of dollars for one post promoting a product. Read more at The New York Times.