I am reading a good book by Daniel Pink called "To Sell Is Human" at the moment,

Hey, I'm reading that same book! It is very fascinating so far, and I recommend it to, um, pretty much everybody.

makes the point that many people who do not think they are working in "sales" actually are. It sounds trite, but he does go into a lot of useful detail and advice from there

Yes, exactly. The premise might not exactly be an earth-shattering revelation, but the book is fascinating nonetheless.