Wilbur Daniel Steele wrote a short story about a pastor who visits an observatory, looks through a telescope, and loses his faith when he realizes how large the universe really is. That's kind of what visiting a chain bookstore can do for an author.
I know the stats on books published, but when I walk the aisles and see the number of authors in my genre and then the number of genres total, look at the number of books each author has to offer, and when I consider that most of them aren't done yet, it's hard not to feel like The Man Who Saw Through Heaven: How can I count? What could one more book possibly matter?
Steele's answer is my answer: the Universe is not too big for one person to be noticed. Its vastness simply means that it is big enough for all. And my husband, bless him, demonstrated faith as big as a grain of mustard seed when he murmered in my ear at checkout, "I didn't see your book here...yet."