• All that a user (caller) needs to know is making a phone call, and there after the user just needs to speak, that too in his native tongue. Hence the ease of use, instead of grappling with more complicated user interfaces, such as the touch tone-based systems. The telephony SLI systems thus remove both technology and language barriers.
• Unrestricted geographical reach made possible by the already dense and growing telephony network. This improves customer satisfaction, but at reduced operating cost, as it cuts the human resource and infrastructure requirements for such a global reach.
• SLIs tend to create quicker caller interactions and hence reduce telephone network costs on toll free numbers from 5 - 50% (survey results quoted in reference [1]).
• Automated systems relieve expensive human resources from routine tasks. The human resource can be deployed for more complex tasks.
The SLIs have an ever courteous and pleasing voice, where as a human operator would wear out by the end of the day and tends to grow irritable and impatient. This improves customer satisfaction.
• The SLI systems are reachable 24 hours a day, 7 days a week. This improves customer satisfaction.

Thus, SLI systems will more than pay for themselves. The Return on Investment (ROI) has been seen to be within 6-12 months.

Other intangible benefits derived by using SLI systems instead of the touch tone-based IVR systems are:

• Unlike the conventional wire line telephones, the key pad is on the cellular phone itself. Therefore every time the user wants to press a key for a menu, he/she has to take it away from the ear, look at the key pad and then press a key. This is very tedious. In SLI, the user would just have to speak.
• Secondly, the diminishing size of the cellular phones makes it very difficult to press a particular key.
For applications where the amount of information available is vast and diverse and the complexity of the menus is much higher, touch tone-based navigation is impossible. This is because the number of options is so large that it becomes impractical to announce all the options and the corresponding digit sequence to be pressed for selecting an option. This is where ASR becomes a necessity.
• The law in many countries including India prohibits the use of cellular phones by the driver while driving, for safety reasons.

Hence, if the customers who have a long drive to get to their work place or whose work demands that they be on the move during the discharge of their duties, the automatic systems are not useful unless they can respond to the user's commands on a hands free kit.