For creatives: Dextra is an app for musicians, filmmakers, actors, models, photographers, writers, dancers, artists, designers, and people with ideas, to collaborate with people from around the world who have the skills to realize their creative ideas.
For marketers/agencies: Massively Collaborative Projects. It enables businesses to involve several (as many as 30, 100 or even 1000) influencers & content creators to work on a single project (like an ad), or several different pieces of content (like a 1000 articles for their blog, or a 1000 videos for their channel) together. This enables the business to talk to the entire community with just one point of contact, to both create & distribute content in large volumes. Additionally, the cost comes down significantly because of the cross promotion involved for the collaborators, the reduction of effort due to the collaborative nature of the project, and the virality potential due to the massive scale.