Unfortunately Hive itself is not a good example of marketing, with it´s 10K or so users. Even platforms like VK attract millions of users despite not paying for content or curating.
For companies it is too much of a niche, maybe Leofinance with its way easier onboarding can change this in future. Not Tesla, but rather some Fintech companies could use it then as a social platform and token tool.

But there is another reason which makes Hive not attractive for marketing purposes: the lack of control. Companies need to control the content on their webpages, they don´t want e.g. some negative feedback on their products. Imagine some Tesla car batteries explode like happened before and customers start ranting around and complaining. On Hive any such comment would stay forever - not good for a company´s reputation.