Who reads us?

A blog is the most public of private places. A stray comment left by a reader serves to remind me of the vast amounts of traffic that finds and dismisses, or enjoys, the words and thoughts put down here.
Who reads this? Why do I, why do all of us write?
Mostly because writing is happiness. But nothing answers this more aptly than the following words by Nathaniel Hawthorne in 'The Custom House' , The Scarlet letter in 1850.

This is an edited excerpt:

'When he casts his leaves forth upon the wind, the author addresses, not the many who will fling aside his volume, or never take it up, but the few who will understand him.......As if the printed word, thrown at large on the wide world, were certain to find out the divided segment of the writer's own nature, and complete his circle of existence by bringing him into communion with it.....
But-- as thoughts are frozen and utterance, benumbed unless the speaker stand in some true relation with his audience- it may be pardonable to imagine that a friend, a kind and apprehensive, though not the closest friend, is listening to our talk. '