Eventful Inc., the San Diego-based digital event promotion service, has surpassed 20 million registered users, making it “the largest aggregated audience of local entertainment seekers in the world,” the company said June 27.

The business that was founded here in 2004 lets users not only find events they’re interested in but provides platforms to share that information with others and to join groups that are interested in the same or similar events.

Through its Demand It! social media platform, the company gives fans of a particular musician or entertainer the chance to solicit that person to make an appearance in their city.

According to Eventful, about 25 million “demands” have led to an estimated 150,000 crowd-sourced events, and more than 450,000 musicians use the service to schedule shows where they received the highest demand.

Eventful’s service works both for consumers of entertainment and advertisers that want to target their messages to particular groups, the company said.