Michael,
The uptake of your application will depend totally on how it is designed and how easy / intuitive it is for the users. Done well, you could achieve success in the region of 70-80% even with such a wide demographic. I see from your website that you already offer online payment - it should be possible to utilise the same processing and integration if the correct solution is selected (you need one that supports VXML).
You should also look at whether this is the best use of IVR - 6% is a relatively small number. I have no idea of the number of calls you handle per day, but if you are starting from scratch, there could be a relatively high initial cost for a relatively low volume service. It might be better to look at where else the technology could be applied to give you a better return on investment - for example, change of address, ID&V, etc.
Happy to discuss further if you need more help.
Dave |