Can you name one advertisement you’ve seen recently from Tesla Motors themselves? Tesla does not spend millions of dollars оn a traditional ad campaign. They let us boost on it while discussing their product and sharing our impressions about their e-cars with others which is called viral marketing campaign. Tesla Motors have neither advertising department, nor an ad team even. 
It’s true that Nissan, GM, Toyota, and Ford have deep marketing budgets that allow them to run some of the most creative advertising campaigns to date. However, Tesla Motors doesn’t have that luxury, yet. Tesla’s capital investment is used to lay down the foundation for tomorrow’s success.