How can we make a product stable?

There are certain methods and phenomena to stable any product.

1- Stability in terms of sales 

2- Stability in therms of shipping

3- Stability in terms of shelf-life

4- Stability in terms of production

5- Stability in terms of quality control & quality assurance.

Every scenario is different and needs special circumstance and method to keep a product stable. 

By advertising the product,  assuring its good quality and of good quality. Also, by seeing to it that the price is justified by the product and it's continually meeting the market's demands and expectations.