I find Dan Brown's use of the word fact charming. Fact: I'm powerless to say precisely what he means by it.
In a culture supersaturated with information, overwrought and overstimulated by media, none of us is immune to the allure of truthiness. With our attention stretched thin and largely confined to the surface, we are forced back on our intuition, to some reflexive sense of what “feels true.” Enter The Da Vinci Code. With the benefit of hindsight we can say the novel got noticed because of able marketing, and because it played into the manic milieu of truthiness.