Vidcon’s first full day on Thursday kicked off in Anaheim, bringing together more than 20,000 attendees to meet their favorite digital stars, network with other creators and pitching potential business deals with brands and advertisers.

The gathering at the Anaheim Convention Center is the ninth iteration of the annual confab which brings together online video industry leaders, content creators and fans. Thousands spread out over the convention center campus, walking through the convention hall where brands like Nickelodeon, Lego, Gushers candy and others had elaborate, interactive booths. Facebook Watch’s booth featured various rooms for social-media friendly photos.

The massive presence of exhibitors and others mark an evolution for Vidcon from its early days when roughly 1,400 people attending the first convention in a hotel ballroom in Century City.

Vidcon’s maturation is evident in other ways this year. Viacom acquired the conference in early February, and a number of Viacom...