Shoppers trust strangers' reviews more than any ad. Reviews are free salespeople — but only if you actively collect and display them.
Next to the buy button, on the homepage, in ads and stories. Real names/photos (with permission) multiply the effect.
Thank positive reviews briefly; answer negative ones calmly with a solution. Future buyers read your replies as much as the reviews.
Bottom line: build a simple ask-display-answer loop and your customers start selling for you.