[nl]

Circles is a great marketing feature.

By pushing the privacy aspect of Google+ it allowed Google to differentiate themselves compared to Facebook. That message has persisted.

Users say they care heavily about privacy, but in practice they don't[1]. Circles isn't a bad solution to that, except for the small minority of people who feel the pressure try to build themselves a compete categorisation of everyone they know.

[1] Occasionally people do care - picture sharing is one case where people are somewhat careful. Circles caters to that case quite well.