The problem they solve is how the end customer of their client finds the product they are looking for. Now, you have to use keyword-based queries: take Amazon, where you type "SD-cards" in the search box and get an endless list of vaguely relevant products as your search results.
What Branch AI offer is a conversational interface where the end customer explains what they need and suggests results that are fine-tuned to your specific query based on embeddings, rankers and query rewriters. As their client, you give them your product catalog, which Branch AI use to train catalog-aware embeddings.
Could have thought of this myself.