In some cases, the items have been reformatted locally for online presentation. When you answer, you find it's not a call from a friend or family member, or even from work. If you are listed in the phone book, they simply may have looked in the White Pages.
Several companies compile national phone directories.
These companies use local phone books from all over the country as well as other sources to compile these databases. The phone company and other businesses also publish directories which list people by street address or phone number rather than name. Another common way telemarketers obtain your phone number is when you inadvertently give it to them. If you sign up for a contest or drawing, a phone number is usually requested. Such give-away promotions may have less to do with gifts than they do with obtaining your number for a sales pitch.