NEW YORK: Some 40% of marketers say they plan to conduct independent audits of Facebook's metrics concerning audience reach and ad delivery, a new survey has revealed.

According to Advertising Age, research firm Advertiser Perceptions polled 399 executives from some of the top-spending marketers and agencies, and uncovered widespread scepticism about the social media network's claims.

Half of these advertisers said they would not spend money on platforms they consider to be risky, while two-thirds reported that they are now questioning their investment with Facebook.

It seems that Facebook's acknowledgement of repeated errors and miscalculations at the end of last year has dented confidence in social media advertising as a whole, which now stands at below 50%, according to the survey findings.

And that decreasing confidence is translating into marketers' decisions about budget allocations in 2017, with just 8% of respondents saying they plan to spend more on Facebook than Google compared with 36% who intend to spend more on Google rather than Facebook.

"Facebook can't go whistling in the dark now," said Kevin Mannion, Chief Strategy Officer at Advertiser Perceptions. "While they've built up too much goodwill and success for the metrics restatements to automatically erode spending, they need to take the lead in third-party verification," he continued.

"Digital advertising platforms can’t assume that trust issues will blow over. No matter what is being said in meetings or from conference stages, the biggest ad buyers are clearly apprehensive."

However, while the survey pointed to concerns about Facebook and greater confidence in Google-dominated search advertising, the industry is unlikely to see a major transfer of budgets away from digital advertising, according to Rob Silver, SVP of Media at digital agency SapientRazorfish.

"We are not seeing any of our clients pull away from digital platforms and shifting to TV or more traditional channels," he said. "The audiences and targeting enabled through digital are simply too important."

Data sourced from Advertising Age; additional content by Warc staff