There should be a like button on each product which a user can like and that product gets added to the Like List of the Customer. (This is different from Wishlist)
There could be a wall which can then be created with the most liked products displayed on it with no. of likes mentioned in each product. There are more chances of then the product with more likes being sold.
Also if a customer likes a product and if the product is out of stock then as soon as the stock is replenished the customer should get an email that he can buy the product now.
Also we should be able to send regular emails to customers for the products that are liked by a customer if a discount is available on the product. This will help in increasing the orders.
Also the customer should be able to share his like list to his friends etc. through social media and then he can act as an influencer.