It’s a smart move, says Peter Weddle, an HR and recruitment consultant. “Employment sites are going to have to expand what they offer, and Yahoo is doing that. I give them credit,” he says.

What Yahoo HotJobs instituted is called “vertical search,” meaning that a job seeker is offered all the positions that match the search criteria, regardless of where the job is posted.

Analysts say that while it is premature to write the obituary for paid listings, it wouldn’t be wrong to say that dramatic changes are in store for the commercial job boards. Vertical search has the potential for leveling the playing field by providing as much visibility for a job posted to a corporate site as to a paid site. If that happens, recruiters will start to ask: Why pay?

“This is the beginning of the end for Monster and CareerBuilder,” says William Warren, executive director of the DirectEmployers Association and a former president of Monster.com.

While Yahoo HotJobs by itself has the clout to change the job search dynamics, Google also is expected to enter the recruitment field when it introduces what is rumored to be a classifieds search program. Company officials have no comment on the speculation, but Silicon Valley insiders say it’s only a matter of time before Google jumps in.

HotJobs, CareerBuilder and Monster postings already are listed in searches done on Google’s powerful search engine. Job seekers just enter a city and a job title and they can find jobs collected from the big three boards.

For recruiters, Yahoo HotJobs’ move means that human resources departments will be able to make a business case for building and maintaining corporate recruiting sites. If companies can get the same results posting to the company site as to a job board, then it makes sense to invest in the company site and save the posting fees.

But it also means it will be harder to get results. If a company is recruiting for an accounting position in Chicago, its listing might be one of hundreds to turn up on a search.

And that’s why Dan Finnigan, executive vice president and general manager of HotJobs, says he doesn’t see the paid job listings business going away. But paid listings alone, he says, will be insufficient for recruiters.

“They will need and require additional recruitment tools,” he says. And those are tools that Yahoo HotJobs just happens to be able to provide.

—John Zappe