>This feature is a bit different as it allows you for example to crosspost the work of a poet you find into a poetry community they didn't know existed - and reward them. It is pretty powerful.

As I posted above in a comment. Once there are thousands of communities and SMTs, it can be a great way to pull in relevant content. For example, if you have a market Friday community, and come across content that might fit but isn't in there, you could potentially crosspost a new account in and get them a bump reward from the start using your own support network.