To be successful, it's regularity that counts on Pinterest. Ideally, you should publish a pin every day, i.e. around 25 to 30 pins a month.
If you don't have many products to show, you need to alternate content around each product (tutorials, ideas for use, a top 10...) to diversify your pins, even if the redirect link is often the same (the product link).
On Pinterest, DIY pins are always popular, so it's important to offer this type of product-related content.