Both are good and will do wonders on the marketing of the platform, for a busy and highly optimized forum signature campaign is a perfect choice, it is effective for branding people tend to trust brands that they have always seen, Coke, McDonald and top brands do not have to advertise they have a stable consumers but they want to keep the brand awareness, they want people to embed their brand to the consciousness of the consumers.
On the review campaign, potential consumers will see the values and the features of the platform, and from there, they can decide if it is the right product to use for their needs.
They have specific goal and results so its worth it if the platform has these two campaigns.