Enhance high ranking on Search engines
Specific countries have search engines that allow sites to rank high. For instance, China uses Baidu, Japan uses Acara, and France uses Voila. In this essence, if you use multiple languages, you will have high chances of appearing at the top on different search engines. As you know, many people all over the world use different search engines to look for the best deals. Hence, using multiple languages will increase your chances of appearing at the top.