- Each replica incurs cost, calculated as `cluster size *
  replication factor` per second. See [Usage &
  billing](/administration/billing/) for more details.

- Increasing the replication factor does **not** increase the cluster's work
  capacity. Replicas are exact copies of one another: each replica must do
  exactly the same work as all the other replicas of the cluster(i.e., maintain
  the same dataflows and process the same queries). To increase the capacity of
  a cluster, you must increase its size.