As noted above, both sites are primarily "social photography" sites. Both sites seem to place an inherent value on popularity over quality of photography and associated feedback. Flickr still seems to have more cred than G+. When I was active on G+ two years ago, it seemed that most of the participants were Google employees and a few "Internet" photographers whose primary skill was self-promotion.
I do know several photographers who have sold images via their presence on Flickr. Agents and art buyers looking for an image of a particular subject will search Flickr. That's not to say that Flickr is a requirement for selling images, but it is an avenue for visibility. I prefer the control and peace and quiet that Smugmug offers. And, speaking from experience, if you configure Smugmug right, an agent will find your work there.
Originally posted by John Elger You do photography for a living? Cool! Can you check my work on flickr (link in the signature) and give me some feedback? Thank you.
My favorite image of your stream is the one of your grandmother and grandaunt. It had the most soul and seemed like the most original.
M