The basic strategy of a drip$-$drip$-$drip campaign is to:

$$leak$$ information to selected trustworthy journalists, high$-$profile social media influencers or other notable figures.

overwhlem the public with a barrage of publicity as a starting point, then slowly pull back the amount of marketing as an event or product release date gets closer.

create a word$-$of$-$mouth campaign using the small$-$world principle: one person tells two other people, they each tell two other people, then two, then two and so on$.$

produce a steady output of information to generate public interest in and anticipation of a forthcoming product or event.