My normal rule is if I get to page 10 I'll finish the book - some like David Peace might take a few goes to get going, but opened an electronic library copy of "The Fall of the House of Wilde" this morning and nearly gave up with this as first line of preface
"Without Wilde’s very modern genius for self-promotion, conceivably, there would have been no David Bowie or, indeed, Kim Kardashian …"
Which I realised was a picked comment on the book, not the author of publisher.
Any one got any other rules they apply?