Drunks, keys, and streetlights: it's where the light is.
Yes, that's a weakness of the study (I'm the numbers guy), but it's also what's available. It also allows for direct comparisons with other platforms offering public posting. And in the face of a dearth of quantified metrics from Google, offers a data point.
And there's a reason why Google is hiding or manipulating their numbers. They're poor. If they were good, you know darn well they'd be bragging about them. So they play tricks and games to try to hide that data.
Yes, that's a weakness of the study (I'm the numbers guy), but it's also what's available. It also allows for direct comparisons with other platforms offering public posting. And in the face of a dearth of quantified metrics from Google, offers a data point.