I have a simple WCF Data Services service and I want to expose a Service Operation as follows:

[System.ServiceModel.ServiceBehavior(IncludeExceptionDetailInFaults = true)]
public class ConfigurationData : DataService<ProductRepository>
{
    // This method is called only once to initialize service-wide policies.
    public static void InitializeService(IDataServiceConfiguration config)
    {
      config.SetEntitySetAccessRule("*", 
            EntitySetRights.ReadMultiple | EntitySetRights.ReadSingle);
      config.SetServiceOperationAccessRule("*", 
            ServiceOperationRights.All);
      config.UseVerboseErrors = true;
    }

// This operation isn't getting generated client side
[WebGet]
public IQueryable<Product> GetProducts()
{
    // Simple example for testing
    return (new ProductRepository()).Product;
}

Why isn't the GetProducts method visible when I add the service reference on the client?