A very interesting question +Sumit Sen
My first choice would be 2 or 3 per week, which wasn't in your question, and seems to be unacceptable to +the g+ resource
, so I marked 1/day as the next closest. My biggest problem with what the majority answer seems to be is how much time it consumes to both prepare a quality photo, properly answer all comments, have fun with it, and learn something from it, plus truly look at what others are doing. If you are retired, or earn your money through photography and already know everything worth studying, or are addicted to G+, or you truly care about the number of people circling you once you have a basic start, then perhaps more posting makes sense. If its just a hobby that you are trying to fit the rest of your life around, then overly frequent posting and too many followers could be a distraction to the real world. I can't think of any of my Canadian friends that would truly want to see 5 images/day from me, so I don't know why my internet friends would want to either. I do like the rhythm of the weekly themes, each of which implies that once per week on a topic is completely acceptable, and gives me the enjoyment of other types of photography.
Although the G+ setup makes it easy to quickly sift through hundreds (thousands) of photos per sitting, I would much rather anticipate a few quality posts with unique information, like yours, than have to sort through quantity when I have time to catch up, which I guess ends up being how I attempt to manage my circles anyway. <end of ramble>