ALL NATURAL LIST GROWTH Grow your list! Opt-Intelligence is the leading opt-in list growth facilitator and operates the largest hosted ad network of its kind. OI’s patented adFWD® product displays targeted promotions to visitors while they register on third party websites. In real-time, the technology matches each registering visitor’s non-personal information to promotions tagged with the same criteria. By explicit opt-in, each visitor has the option of forwarding their contact info to the advertiser whose promotion they want sign up for.