Is the last digit of a phone number random?
- by sehugg
I have a telephony app which has a prompt which requires user choice. I made the app select one of 10 different phone prompts based on the last digit of the caller's phone number. Then I measure whether the user responds to the prompt (accept) or decides to skip to the next step (reject). I thought this would work well enough as a random selection, but I think I may be wrong.
What I'm finding is that the exact same prompt has a dramatically different response rate (25% vs 35%) for two different last digits. Now I'm curious why this is. Does anyone know how phone numbers are assigned and why the last digit would be significant?