"Download our free white paper and enter to win a free iPod."
Some companies just don't get it. By now almost everyone has learned that "download our free white paper" means "give us your email address so we can spam you for the rest of your life." Marketing departments (and their agencies) need to learn that impressions do not have to become sales leads.
You cannot trick someone into buying your product.
What is the formula for success?
Step 1: build a remarkable product. Learn more in Practical Product Management.
Step 2: get your customers to tell their friends. Learn more in The New Rules of Viral Marketing--a new e-book by David Meerman Scott. Download it now; it's free and there's no annoying registration requirement. Forward it with your marketing department.