What are some alternative marketing strategies that could have been used instead of the Google Home of the Whopper campaign?

The Google Home of the Whopper campaign by Burger King activated Google Assistant in people's homes through a TV commercial spot. The specific impact on Google Assistant's usage is not detailed in the provided content, but the campaign was successful enough to win a top creative award at Cannes Lions in 2017 and generate an estimated $135 million in earned media.

The specific information about other successful marketing campaigns by David the Agency is not provided in the content. However, David the Agency is known for its innovative and successful marketing campaigns for various brands. One of their notable campaigns is for Burger King, called 'Google Home of the Whopper', which was highly successful and received a top creative award at Cannes Lions in 2017.

Some potential challenges of implementing a marketing campaign like Google Home of the Whopper could include backlash from consumers who feel their privacy has been invaded, technical difficulties in ensuring the voice command works properly, and potential legal issues related to the use of Google's technology without their consent. Additionally, such a campaign relies heavily on the novelty factor, which may not be sustainable in the long term.