Book publishers offer free sample chapters in the hope that you’ll reciprocate the
favor and buy the book.
That ‘something in return’ need not be a purchase (not yet, anyway).
Persuasion architects know that they need to contact prospective
customers on several occasions before they become an actual customer —
this is why regular newsletters are a staple offering in the persuasion
architect’s toolkit. So in return they may simply ask for a referral, or a link to
a website, or a comment on a blog. And note the emphasis on ‘ask’.
Persuasion architects are not shy of asking for the favor that you ‘owe’
them.