Facebook has issued an update on how it calculates the “estimated reach” advertisers can expect when buying media on the social network with the latest update revealing a further measurement discrepancy with Like and Share buttons on mobile – the latest episode in an issue that has dogged its year.
The social network is updating how it calculates the numbers that appear in its estimated reach tool by updating the methodology for sampling and extrapolating potential audience sizes.
However, the latest update has also identified a discrepancy between the counts for counts of the Like and Share Buttons via its Graph API compared with the counts when entered via a URL into the search bar in the Facebook mobile app (see screenshot).
A post explaining the situation on the Facebook NewsRoom reads: “We have found that there may be a difference between what these metrics count and what the mobile search query counts.”
It goes on to sate that Facebook is currently working on a resolution to the issue, “so that the Like and Share button metrics and our mobile search query metrics match up, and we will notify partners as soon as we have an update,” according to the update.
In September, Facebook found itself in hot water when it admitted that it had been overstating video view times by 60-to-80% for two years, because it was only taking into account views that lasted more than three seconds when calculating its ‘Average Duration of Video Viewed’ metric instead of considering total views.
Sir Martin Sorrell, CEO of WPP, the owner of the largest media buying network in the industry, used it as another opportunity to harangue the industry’s second-largest media owner.
“Clearly it's an example where the player and referee cannot be the same person or where you cannot mark your own homework,” he said at the time. “Some of our leading clients have been very concerned about viewability, along with GroupM, as you also know. It appears that, at last, the dam has been breached.”
The outcry over the measurement of ads’ performance on Facebook – notably that it was ‘marking its own homework – prompted a series of overtures from the social network such as adding more companies to the roster of adtech outfits it will permit to measure performance of its ecosystem (commonly referred to as a walled garden).
This also included the formation of a Measurement Council and increased third-party verification from companies such as Moat and WPP-backed Comscore. When quizzed by The Drum on the regression from its earlier 'walled garden policies', Danny Hopwood, vice president of solutions and platforms operations for EMEA at Publicis Media, said: “Facebook is learning iteratively that it can’t prescribe the success metric”.
Commenting to The Drum on the latest measurement issue, Rob Blackie, OgilvyOne’s global head of social products, said: “While Facebook’s changes are welcome – they are part of a unsettling pattern for advertisers that Facebook metrics are regularly found to have errors in their collection.
“Facebook is now one of the digital giants and needs to dramatically improve their transparency to business users, and to enable more third party auditing, rather than hoping that we will take their measurement on trust.”