Final answer:
The purpose of online reviews is to give feedback on services like Blue Ribbon Taxis' shuttle. They are used to inform potential customers about the service quality.
Step-by-step explanation:
Online reviews serve various purposes, mainly they are a form of customer feedback. In the context of Blue Ribbon Taxis and their shuttle service, the purpose of the reviews would be to provide feedback on the company's service. This means that the correct answer to the question is option 1: To provide feedback on the shuttle service. Reviews help potential customers determine the quality of service based on other people's experiences by highlighting the strengths and weaknesses of the shuttle service, such as customer service, atmosphere, prices, and quality.