The truth is, while they serve the same purpose, they are in no way similar.
But before we dive in though, let’s agree on the vocabulary to be used. “Influencer marketing” refers to a brand reaching out to someone with a specialised and substantial following, to spread the word – in return for an incentive (usually). On the other hand, the term “brand advocates” refers to customers that are so fond of a brand, that they share some of its content on social media and stand up for the brand when things occasionally go wrong. For free.