It is still a bounty campaign similar to what you've seen in altcoin bounty campaigns, if your platform has a token associated with it, you can run a bounty campaign with your token as a reward, even if the token is considered a shit coin many bounty hunters will promote your platform, you can run a signature campaign, social media campaign and article campaigns and your platform will immediately get traffic.
If there is no token or coin attached to your platform you can contact influencers and ambassadors to promote your platform, or if you have a service or a product you can create an affiliate program and invite people who are into affiliate marketing, there will always people who will and can promote your platforms.