I haven't looked at the cover of a book before deciding to buy it/read it in
years. Granted, I get my kicks from reading technical books and history books, instead of storyline literature.
Case in point, the cover of what i'm currently reading:
https://ozon-st.cdn.ngenix.net/multi...1007171774.jpg
And of my favorite book:
https://www.securepages.nl/kadeboeken/plaatjes/6574.jpg
But when I do, I just google the title, read a summary and the reviews on Goodreads (and more importantly, check what kind of people those reviewers are).
However:
What is a complete turn-off for me are "catchy" titles, designed to lure the customer towards it. I automatically reckon it is pretentious, superficial, unresearched bla-bla, and quickly scan the bookshelf to something else.