A Billion Wicked Thoughts: What the Internet Tells Us About Sexual Relationships this is abundantly clear as a huge proportion of the statements in the book are ludicrous as written but which make reasonable sense if you stick 'on average' somewhere in there. The book goes on about how men like this, women like that, gay men like this, and BDSM enthusiasts like the other thing, and it requires the reader to accept that writing 'on average' a few thousand times wouldn't actually help the book communicate more clearly. This means that you can't quote from the book easily without coming off as pretty damn sexist but it does reduce the length of the thing by a good 10% or so I would imagine.
This book has a great deal of interesting information surrounding what we know about how people look for sexual stimulation online. There are plenty of fun and interesting things to learn - for example, it was obvious to me that porn is overwhelmingly paid for by men and erotic literature by women but I was surprised to know that the total amount of money spent on literature dwarfs that spent on porn. I would have thought that the money would have been in fake boobs and terrible acting, not in bad boys who finally confess their eternal love for the delicate heroine.
The trouble with this book though is not the data but rather the conclusions. Like far too many other books that focus on the 'yawning chasm' between men and women this book spends a great deal of time explaining statistical facts with evolutionary psychology. There are plenty of things you can say about porn viewing habits but if you start a sentence with "Back on the savannah men and women behaved like this" you have veered very far from science into the realm of wild speculation. It is useful to consider how monkeys, orangutans, and other primates structure their sexualities but A Billion Wicked Thoughts is too quick to jump from "X is true on the internet and monkey do Y so obviously people are Z!"
If you really don't know much about what is actually out there in terms of porn you can expect this book to educate and maybe titillate you but if you are looking for serious research into how people work you could find a better source. The book is pretty well written for a mainstream audience that is up for entertainment and isn't too worried about the precision of the conclusions but there is just too much questionable reasoning for me to give it any better endorsement than that. It has a lot of neat stuff and made me think about some things but I just can't take it seriously when it so constantly abuses the word Always and so seldom admits doubt. The world of human sexual desire is far more complicated and far less understood than that.