coachm - 4:30 pm on Oct 25, 2012 (gmt 0)
Online presence in G+ would further complement your authority and help in generating more online sales.
Online buyers would be able to know more about your works through peers and circles. So in a way it could be supportive in enhancing sales.
You don't KNOW any of this. You suspect, believe, whatever, but you don't know, and Google isn't saying.
Google NEVER gives enough information about what's in the black box to make for actionable decisions, for anything it does. Some people don't realize that the usually sketchy details given are lacking a huge amount of the iceberg about ALL of the implications of doing something specific -- say using the author tag. Or promoting it.
If there's one thing I've learned over the last years, it's important to distinguish what we know for sure about Google practices (not much), what we think we know, but really don't (most of it), and what we have no clue about (again, almost all of it).
Without the information Google with-holds out of concern for people "gaming the system", whatever you do as likely to work as not work, or have negative unintended consequences. It's all a crap shoot.
I have better things to do with my time than try to guess what google is doing. I'll do my audience a favor.