The social media marketing plan has three main objectives: 1) Make the new store easy to find physically by getting listed on search engines and directories. 2) Build a good online reputation by getting customer feedback on search engines and directories. 3) Promote water conservation on social media by building purpose-driven personas on platforms like Google Plus, Facebook, Twitter, and Pinterest. The plan outlines steps to achieve these objectives, track key metrics, focus efforts on what works, and continue growing the strategy.