Amazon's just made a substantial change - their search results now have a buy button RIGHT ON THE RESULTS. A user doesn't see the blurb at all. Just the cover, title, and that's it. It makes it even more critical that the cover and title convey as much information as humanly possible about the book's length, genre, and style.
For example, my Scottish Lass book used to get people downloading it thinking it was a massive tome and then complaining that it was short. I updated the cover, title, and blurb to make super-clear it was a short novella. But with people now able to get to it without even seeing the blurb, I could be back to getting complaints about its length.
It makes that cover and title quite important in ensuring readers know what they're getting.