As for flickr,
In my mind, it one of the best portals due to the amount of visits it receives, it must be one of the most vital tools to keeping our hobby alive.
It might even be a coal on the fire that is keeping some of our chosen camera brands burning brightly in the commercial world.
Masses of people expressing a interest in viewing images captured by others, novices having a sneaky peak at exif data, looking to learn a little more.
A place where you can see many different presentations a certain piece of equipment can offer.
It was a stepping stone, to my finding NG. It is also a extension to investigate some of the ideas presented to me on NG.
I might visit flickr for 30 minutes a month, but I will always see something to keep me interested.
My latest viewing is the D500+Sigma 500mm f4 HDSM.
"If it aint broke, don't fix it" .