If you believe comScore’s latest figures, Vevo’s viewer numbers are still sliding in the US. The music videos service had 44.8m unique US viewers in July 2012 according to comScore, down from 46.2m in June, and its peak of 63m back in June 2011.

However, that’s a big ‘if’ – as we’ve reported before, Vevo says its growth on mobile and tablet devices isn’t reflected in comScore’s numbers. So, while we can use those to gauge that the average online Vevo viewer watches 13 videos and spends 46 minutes a month on the service, we’re still reliant on the company’s own figures for its overall growth across all platforms.

Vevo has been one of the more transparent services in terms of publishing stats, but the lack of accurate independent metrics is an issue. Of course, global expansion is a big focus for Vevo in 2012, and its figures from the UK, Australia and now Brazil aren’t included in this particular comScore data either.

But with Google (157m unique US video viewers in July), Facebook (53m) and Yahoo (48.7m) ahead of it in the table, the chart does remind us why those three tech giants may be jostling to secure a big distribution partnership with fourth-placed Vevo – or in Google’s case, retain it.