No, and yes. Publicity and advertizing makes a huge difference when there's already a market for the book. It will not, as a rule, cause people who aren't already waiting for the book to buy it.

An ad for the New Orson Scott Card Ender novel will make fans say Finally! I must go buy that!

An ad for the first novel of Unknown Genius will make people pass right by it. Unless they're deeply in the book business, in which case they'll say Huh! The publisher must think highly of this book. I wonder if I can get a free copy?