Google is the most popular search engine in English markets, so if you have physical locations then you need to get these registered as Google Business Listings
Bing is used by over 1 billion people every month, so whilst smaller than Google, it's not a search engine to be ignored, especially when you can register your business for free
Apple Maps is the default mapping system for Apple devices, which make up 28% of the global mobile device market, and as a platform is often mistakenly overlooked
As well as map listings, search engines also like to rank localised web content in their results, so you can see a lot of benefit from creating these pages on your website
Managing 100+ locations can be made easier by utilising third-party software to perform bulk updates and ensure consistency across all local citations across the web