Employment of advertising, marketing, promotions, public relations, and sales managers is expected to grow faster than the average for all occupations through 2012, spurred by intense domestic and global competition in products and services offered to consumers. However, projected employment growth varies by industry. For example, employment is projected to grow much faster than average in scientific, professional, and related services such as computer systems design and related services and advertising and related services, as businesses increasingly hire contractors for these services instead of additional full-time staff. On the other hand, little or no change in employment is expected in many manufacturing industries.