GOOG-411, which will be unplugged on Nov. 12, was the search company's first speech recognition service and led to the development of mobile services like , Voice Input and .

Google, which recorded calls made to GOOG-411, has been candid all along about the motivations behind running the service, which provides phone numbers for businesses in the U.S. and Canada.

In 2007, Google Vice President of Search Products & User Experience Marissa Mayer said she was skeptical that free directory assistance could be viable business, but that .

"The speech recognition experts that we have say: If you want us to build a really robust speech model, we need a lot of phonemes, which is a syllable as spoken by a particular voice with a particular intonation. So we need a lot of people talking, saying things so that we can ultimately train off of that," she told IDG News Service in an interview. "So 1-800-GOOG-411 is about that: getting a bunch of different speech samples so that when you call up or we're trying to get the voice out of video, we can do it with high accuracy."