You’ve heard the axiom that it takes 7 exposures to establish trust and credibility before your prospect makes a buying decision.
Eg. A person sees a mention for a new beverage (eg. a horseradish-flavoured soda) on a website, sees a celebrity endorsement, receives a flyer in the mail, on 7 occasions before they buy it to try it out.
On the Internet, however, I feel it’s probably closer to 5 exposures before trust is established. Perhaps it’s due to the instant gratification, instant exposure and immediate deliverability nature of the medium that lends itself to this.