This little section of Romans establishes one thing: Paul has not been to the Roman church. This makes the letter to the Romans pretty unique, because it is written to a group of people he had not met before, to a church that he did not start. (They were not all strangers, no doubt he knew someone in the church, because the letter had to go to someone.) This is a good indication of the growth of the early church: they were at least connected enough to have some familiarity with believers outside their own city.