Here's the problem. Any corporate recruiter, faced with pressure and an empty chair, will ultimately turn to a third party firm for help. In spite of all the hoopla, search firms and temp agencies can still produce solid candidates on demand. The online services simply don't meet the accepted performance standards. Excluding price differences for a moment, the difference between the performance of Recruiting Firms and online services is huge.
Online services focus on filling databases and administration.
Recruiting firms focus on delivering qualified candidates. While Monster's achievements are revolutionary for a job board, they are nibbles at a larger target. Part of the reason is perspective. Job Board organizations see statistics. Recruiters see people.