As an authority, you may want to mention you could go into it - but would rather focus on the business issues they are having and the best way to address those things. If they press for explanations, I would ask how they feel it might be impacting their leadgen, branding & ROI - could be that they are just spooked by some seo fud marketing. G+ is just another tool in the bag (or evil trick, depending on who you ask). Your client /CEO only needs to understand the resulting value of what you do with it. The people that don't have the funds to invest in you are the only ones that need to learn all of the nonsense of G+L/MB in order to DIY... Along with being their own plumber, locksmith, dentist, etc. Frankly, for those people, there's YouTube. So personally, I think it's probably a waste of your time unless it can spark a more valuable conversation.