The best kind of advertising in film is, oddly, invisible. A product that the characters use, need and integrate into their actions, rather than just a casual shot of a random company logo, is the key to success, and the Ray-Ban sunglasses used in the 'Men in Black' films both look cool, shield their eyes from their bright devices and feature prominently throughout.
The deal clincher is that the duo (who target different demographics – one actor is a veteran Oscar winner, the other is a younger, mainstream box office draw) put them on slowly in unison just before the film's most memorable moments. And they feature in the posters. Following the film's release, Ray-Ban stated sales of their Predator 2 sunglasses tripled to $5 million.