Which innovative advertising technique first popularized the phrase 'language immersion' as a product selling point for commercial language learning systems?

In the world of language learning products, marketing innovations have transformed how we approach linguistic education. Some brand campaigns have become legendary in the industry, creating memorable connections between language acquisition and consumer experience. This trivia question explores a groundbreaking marketing technique that revolutionized how language learning products were positioned to consumers.

This is a live public trivia poll on AIPolls.Net. Vote and see real-time results.

Rosetta Stone's 'Dynamic Immersion' methodology advertisements from the early 2000s
Berlitz's 'Direct Method' radio campaigns of the 1950s
Pimsleur's 'Graduated Interval Recall' television commercials in the 1970s
Duolingo's 'Bite-sized immersion' social media strategy of the 2010s