Google+ not having the potential for marketing yet. However, right now i am doing with facebook and getting lots of results (visitors, leads, conversions). This is all what we've expected through social media optimization/marketing/promotions.
Nope. Google + is like a ghost town that i will not put too much effort on it . I only use it to improve SEO. Fb still the best place to promote products. It full with lot of application that allow you to push your products well in fb.
I think its facebook. Reason being, that although a lot of people have joined google plus, they actually dont use it since they are already using facebook.
Right now, Google+ has not yet gained enough popularity to be an effective and efficient platform for marketing. Facebook would be a better option.