The system we use for our customers is supplied by a firm in Grand Rapids, Michigan and warranted for 10 years. Their written guarantee lists what is and is not covered In our case, if a stain does not come out after recommended cleaning, that stained part of the upholstery will be replaced under warranty. If the fabric is unavailable, the company will work with the consumer to find a solution to the problem up to the amount paid for the item stained.
It’s best to become familiar with the policies of the sources you work with. I am aware that this type of service can be performed in the home after delivery of the furniture, but not all providers allow this. Some restrictions only allow for pre-delivered goods, others have restrictions on fabric, still others state residential use only.
How well does the system work? A good number of my customers told me that they had purchased this program with new furniture. They were very pleased upon learning that their reupholstered pieces could have the same protection.
A few years ago after our youngest left the nest, I reupholstered our family room sofa and applied the stain protector. A year ago one of the grand children spilled some strawberry pop on the sofa. It blotted up without any staining. It works!