One popular Marian devotion is the saying the rosary, a thousand-year old practice, and in many of her perceived appearances at various times in history of Our Lady has endorsed this devotion. Praying the rosary is significant to many Catholics today, but many also ask: what good does it do? What's the use of saying the rosary? Well, it is a prayer; and praying it with simplicity of heart as an offering to God is its own excuse for doing so. A question like "what's the use of falling in love?" will never be asked by one who has fallen.
Others say that the rosary is meaningless repetition of prayers. Well, it is if it does not achieve its purpose , that of rapport with the Lord, but remember that if with each hammer blow a concrete nail bites deeper into the concrete, no matter how small, the action is useful. Each traffic light I pass on the way home may be a repetition of a previous one, but I realize that I am heading closer to home.
Even if the rosary is monotonous and boring, it can be an excellent opportunity for the virtue of patience grow in you. Christian spirituality is basically rooted in patience, and when we say that we were saved by Jesus' sufferings on the cross we really mean the patience with which he bore his suffering. And so the rosary, said with patience, can be enriching.