Earned media refers to your own media that is shared or applied by others. Your content has thus actually earned the attention it receives. This could be the sharing of a social media post, a mention of your product on another website, a press release or a video on YouTube recommending your product. The use of earned media is therefore entirely free, because you have not paid for the content that others create.
In fact, earned media is the most effective form of marketing, because users are genuinely enthusiastic about your product or service and want to share it with others. Credibility is therefore very high, which can strongly influence buying behaviour. This makes earned media very SEO-proof, because every 'recommendation' ultimately leads to better findability in search results.
The disadvantage of earned media is that you have no control over the content. It can therefore happen that you receive a negative review.