Plant growth-promoting microbes can affect the plant microbiome, improving different properties of the plant such as yield and health. Many companies are commercializing these microbes as products called biologicals. Defining the product concept is one of the first and most important steps in making a biological product. Companies can use phenotyping and genotyping approaches to identify the microbe to make into a live bacterial product. Screening usually begins in the laboratory and often moves from high-throughput methods to more time and resource-intensive methods culminating in large scale field testing. Once the microbe is chosen, the fermentation process grows the bacteria to the necessary amounts, while the formulation process ensures a stable product in the desired form such as a liquid or powder. The products must show yield increases in the field over several seasons and conditions, but also must be easy to use and cost-effective to be adopted by farmers and other customers. Tying all these data together from the selection process to test results gives a customer a ‘reason to believe’ for the marketing and launch of a successful product.