Does Telemarketing Still Work?
You can take this [outcome] to the next level. If you have a file of people with whom you have an existing business relationship but struggle to get business from them, and if you're able to get their permission to call them, they're likely to buy from you when you do call. By giving you permission to call, they've signaled that they are probably interested in your offers.
You can't guess who's going to buy, but you can target your efforts to those who don't mind your calls and are likely to buy from you.