I've been wondering about sales of the a7/r series and the breakdown between the two models, but it seems sales data is a well-kept secret - too bad.
I did come across some info from Roger Cicala on rental volumes and found it interesting so will pass it on:
'rentals of both A7 and A7r have been strong. We rent more A7/A7r than all other Sony alpha and NEX cameras combined.
Last year micro 4/3 rentals were about double Sony rentals, this year they're about even largely because of the A7 increase.
Looked at another way, micro 4/3 bodies and A7/A7r rentals combined are about equal to all Nikon body rentals. Last year they were about 1/2 of Nikon rentals (some of that is because Nikon is down again this year, but mostly because m4/3 is up slightly and Sony up significantly). '
You would have to caution against using rental volume as a proxy for overall sales, but the level of interest appears to be strong, even in the notoriously conservative US market. Looks like they have arrived, and superior image quality matters to a lot of photographers. It might be better for them elsewhere, especially Asia.
Sony has already won the image quality battle and has the fundamentals in place, now for the refinements and system development and maturation to move closer to C/N who have had decades to perfect their systems - sales success is all about overcoming objections and countering reasons not to buy.