Write SQL query to solve given problem: How much is the annual revenue of the customer with the most number of shipments?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T2.annual_revenue FROM shipment AS T1 INNER JOIN customer AS T2 ON T1.cust_id = T2.cust_id GROUP BY T1.cust_id ORDER BY COUNT(T1.cust_id) DESC LIMIT 1