Interesting quotes about reciprocity:
"Another interesting aspect about reciprocity:
when they return the gift or favor, that gift or favor may be different in value than the original gift.
Usually, they(clients) won’t reciprocate with something of lesser
value—that would leave them with a feeling of an unpaid debt. Often, they
reciprocate with something of higher value than the original gift. " - SUSAN M. WEINSCHENK, PH.D.,NEURO WEB DESIGN : what makes them click? p.45-46