[Pavel]

I use Flickr a lot - there are specialized groups there for just about anything photography. If you wish to learn, it is a great place. If there is a topic which interest you/wish to learn about, you can start a group within minutes and if the topic interest others, have a viable quorum within a couple of weeks. Lot of it is a crap of course, but after a while you learn your way around and can avoid much of it. The content is what matters to me most of all, interface is more important to more sophisticated users. For me Facebook is too much like a voluntary invasion of privacy and too unfocused on photography. Flickr is clearly about photography and i like that. I know little about Google+, although I am a member. Frankly, at this point Flickr meets my needs to communicate with fellow photographers quite well and so i do not feel compelled to look elsewhere. I still prefer face to face meetings, but that is a whole new topic.