In a word...hundreds.
You aren't known as well as the kitchen sink. You have no big advertising group behind you pushes you into the limelight and making you a household name. Several big advertising groups say it takes on average of ten exposures before a person will buy a product. These for an author is public appearances, book signings, tweets, Facebook posts, Pins, posts in GoodReads, etc.
The results- No sales.
Keep writing and loving the Lord.