Just lately I've been involved with two writing groups: one real-life group, meeting at my local library, and one online group through Facebook.
The library group had been reading their work aloud to each other, but I went to talk to them about the all-important opening to a piece of writing. We looked at twenty-one openings to novels and they gave their impressions. There were a few surprises, especially when someone said they hadn't liked the first few sentences I'd quoted, but then found out it was one of their favourite novels! Just goes to show . . . something, but I'm not sure what.
Maybe some of us are more inclined to give a book or story a chance than others. One member of the group said they always read the ending first, but she couldn't say why exactly. Others said they were influenced by reviews, and might read for longer if the review had suggested it was their sort of story.
The online equivalent of browsing in a bookshop is Amazon's 'Look Inside' or getting a free sample sent to your Ereader. That makes it more important than ever to ensure your opening chapter is a compelling read.