A couple of days ago I was at our local grocery store to pick up some food, and I personally took the picture posted at the beginning of this article. This is the actual book display at our grocery store. Do you notice anything that stands out in this photo?
If you answered "all of these books are bestsellers, or written by bestselling authors," you would be absolutely correct. There were no books by new, unknown authors stocked at the grocery store. They will only stock bestselling books, or books written by bestselling authors. The grocery store wants to sell books that they have a reasonable expectation will sell, and sell quickly. If a title is by a relatively new, unknown local author, the grocery store manager (or more likely, the book distributor for the grocery store) has no idea how the book will sell. They are taking a risk by agreeing to stock it, and in these economic times, nobody is willing to take much of a risk.
The same goes for the big box pharmacies such as Walgreens or CVS, or the big box stores like Wal-Mart, Sam's Club or Costco. These stores buy in large volumes only, think thousands and thousands of books. They get the books at steep discounts from wholesalers, and they only get books that they have a pretty good idea will sell quickly. These stores will not let stock sit on their shelves for long. If the book, or any other item in their store, doesn't sell then it is going to get yanked from the shelves and sent back to the publisher or manufacturer.
With this being said, I have had authors who have sold books in these venues, but their book was not stocked by the stores. Instead, they did a local book signing event in their area on a consignment basis. That means the author had to bring their own books to sell. The author got exposed to hundreds of shoppers the day of their event. The store looked good because they were seen as supporting a local author. However, these events are few and far between.
In order to one day see your book actually stocked on the shelves of these venues, it has to become a good seller first. That means doing the legwork at smaller, local events, reaching out to your niche audience, attending book fairs and festivals, doing speaking engagements, etc. Trying to get a book stocked by one of these stores before the author or the title has developed any kind of sales history first is like trying to bake a cake while skipping the first five steps of a recipe. Those efforts will fall flat. There are always exceptions, of course, but that is just what they are, exceptions. They don't happen often.
Develop a plan to start locally first, and then expand from there. Remember, every author has to start somewhere, but more likely than not, that won't be in a Wal-mart or Costco store.