FortiWeb is Fortinet's web application security system (or web application firewall, WAF) featuring advanced vulnerability management and threat detection and prevention, available in deployment as an appliance or virtual appliance, also as a hosted or a cloud-based virtual solution.
Most of them have the same features but not for FREE. The second point was the total cost of ownership for 3 and 5 years. Fortinet supported us with the best prices for 3 years and 5 years as well with advanced hardware replacement against the others.