That’s according to tech firm Integral Ad Science, which released research today showing that most of this paid traffic is, in many ways, less valuable to advertisers than their free counterparts. Browsers under the influence of bribery have less spending power overall, making conversions anywhere between 65% to 82% more expensive than other sites across web. Not only that, but it’s close to impossible to target these internet users behaviorally, causing headaches—and wasted money—for the advertisers on the other side.

“In the industry, it feels like everyone’s generally pretty wary of bots, but they’re not thinking outside of that,” explained Evgeny Shmelkov, an IAS senior data scientist who led the study. “You might be thinking everything’s fine so long as you’re ultimately advertising to a human, but we found that’s not actually true.”

Read the full article from Shoshana Wodinsky in Adweek.