There are different forms of marketing through "social media influencers", have you tried any and what has been your experience?
For several of my online businesses, I have tried promoted posts and sponsored posts. Let me explain the two.
The promoted posts that I am referring to are easier to spot as advertisements. Influencers will have a post showing your item or website and/or a clickable link in their profile. This post will be shown for the amount of time agreed to and deleted afterwards. I have found this method to be more affordable, but less effective.
The other method I have used is to send products to influencers who embody the brand and have a high number of followers and engagement. In exchange for the free item, they will incorporate it naturally into a photo or a post. This is a more subtle way of advertising that not only showcases the item, but also comes with the influencers' endorsement. Most oftentimes the cost for this is the product itself and shipping. For very valuable influencers with massive followings, there will also be their cost attached as well. While this isn't the cheapest way to use social media marketing, this is my preferred method and I have seen the benefits and ROI to be better than through promoted posts.