I'm sick of all these samples that show almost nothing. Usually there's only a few pages, of which most of them are only the table of contents and an intro. This is never enough to judge whether or not the book might be interesting. Barnes & Noble, please give us the first chapters as the sample. Until then I will not buy any book whose sample is rediculously short.
Complain to the publishers. They establish the sample content.
Try visiting the author's website. Many authors feature samples on their sites, at least one chapter and sometimes 3-5 chapters for novel-length works.
I've all but given up on BN samples. They just take up space on my device.