The challenge for Twilio is that phone #s are a fixed quantity. The same #s have been circulating across lots of different companies including being used by spammers and in marketing campaigns and published across the Internet. Make sure to search the Internet for any phone # you acquire from Twilio before buying it. It may already have substantial call spam/undesirable organic traffic associated with it.

On the flip side, there are already companies out there specializing in monetizing misdials. They specifically look for phone #s that have been retired recently with a lot of volume and then take those calls and resell as leads for cars, insurance, etc.