I think it is too soon to suggest that Monster will go the way of the newspaper classifieds, for a few reasons:
- Vertical search engines currently aren't charging employers to post with them; most of them make their money with Google adwords
- Why not charge employers? Because they would need to have a whole host of staff to market their service, as well as an accounting department to deal with invoicing and hunt down the people who don't pay for their ads
- Most vertical search redirect the job posting not to the employer site but to the original posting on a job board. Monster never redirected a job seeker to a local newspaper because the classified service just dealt directly with employers and got paid for it.