Same here it’s the cover and the title so as synopsis is to follow. Why? Simply ‘coz it’s the first you seen in particular when your meters away from it.
For regular books, I lift titles from anywhere. Like watching the movie Blade Runner and the end credits give the source as Philip K. Dick's 'Do Androids Dream Of Electric Sheep'. I'll add that title to my list. For e-books I check out titles in the signatures of forum posters that give intelligent responses. For research I get my titles from the subjects. I read book reviews in literary supplements. Get recommendations from friends and peers. And I'll check for new titles by familiar authors.
My list started with literature I havent read but should have at school so origionally it contained books like LOR and Jane Austins novels, War and Peace, as I browse the second hand shops and see other titles my list gets longer and shorter as I read, add and delete books from it mentaly. I have bought books on my list that I havent read yet, shamfully, but I will get around to them, I bought the illiad and the odyssey last week for £5 but reading Jane Eyre at the mo which is lovely.
the colour scheme. If I want to read a happy book, I will notice the happy book first. If I want a slasher book, I'll go for the the one with the blood on the cover. The font of the title is important too, since a plain one may not be interesting whereas a graffiti-style of writing may be illegible.
I probably notice the title most of all. Titles that usually interest me are ones that I have to ask questions about. Then the cover art and author, but those don't really affect if I want to read it or not.
