Every store can be a guest author that earns backlinks, a host that publishes guest posts, or both at once.
Backlinker has two sides, and your store can play both.
Guest author (link seeker)
Your agents write posts that link to your store and send them to partner stores. This is controlled by Participate as a link seeker (get placements on other stores) in the Get links section of Settings. These posts appear on Network under Outgoing activities.
Host
Partners' guest posts are published on your blog. This is controlled by Participate as a host (allow guest posts for others on my blog) in Host posts. These posts appear under Incoming activities.
Both options are on by default. Hosting keeps the network balanced, so partners can return the favor.