Abstract: A computer-based aggregated security investment service interacts with one or more customers via one or more communication links. The service allows multiple customers to execute aggregated purchase orders of securities in dollar increments. Customers setting up accounts have the ability to select numerous different types of individual, joint, conventional, or tax advantaged accounts. The present invention also provides a mechanism for reducing the exposure of the investment service to purchases of securities with fluctuating prices by staggering share purchases as two or more sub-orders. Finally, the present invention provides a method of producing customized communications for users associated with a non-affiliated organization without requiring separate hardware components for each organization.