Never bought a book like that (except at used bookstores) but I do that often in libraries, I just pick up something totally random on the shelves (I'll check on Goodreads if it's part of a series, though, and will change to the first in the series if needed).

I'd say my success rate is about 75% liking the books, which is higher than I expected.

I often end up always reading the same authors and styles, it's great to find new things to read.