Data brokers are businesses that compile and sell personal information to marketers, creditors, employers, private investigators, and virtually any other party that can prove it has a professional interest. What the brokers charge for personal data varies. But here are some examples of what different pieces of information can fetch when served up a la carte by major commercial data vendors.

Date of birth: $2.

Address: 50 cents.

Social Security number: $8.

ZIP code: 50 cents.

Marital status: $7.95.

Employment information: $13.

Education history: $12.

Published phone number: 25 cents.

Unpublished phone number: $17.50.

Cell-phone number: $10.

Driver’s-license information: $3.

Figures courtesy of Preemptive Media. For more information, go to www.preemptivemedia.net.