According to this well-argued article in Geist, booksellers are transfixed more than ever these days by sales figures, conveniently provided by Booknet, etc. -- and this leads to benighted decisions. If a literary writer doesn't sprint from the starting blocks to the top of the best-seller list with his first or second effort, he's dropped like a hot potato. But isn't it better, betimes, to be a hot potato? A great many outstanding writers didn't come into their own until late middle age, after producing a number of works that, whatever their merits, did not fare well sales-wise. Read all about it here.
How does the situation affect poets? Well, we have always been under the radar in that sales game -- but surely the current over-reliance on such crude, utilitarian indicators as sales figures will keep us ever farther from the Chapters/Indigo shelves.