The New York Times this week noted a raft of new start-ups with names like Indeed.com, SimplyHired.com and WorkZoo.com, each offering job listings aggregated from the big job boards like Monster.com, CareerBuilder.com and HotJobs.com, as well as hundreds of smaller job sites. By now, the idea of aggregating other people's content is a fairly tired one, but in this area, it actually makes sense. It also portends real trouble.

Meta-search engines were perhaps among the first aggregators, and they flourished in the early days of the Web because at the time, all the major search engines were largely solo acts, and none even began to approach comprehensiveness. In that environment, a consolidated search of multiple search engines provided real benefits. Today, however, with the major search engines all providing much better coverage, and with many of them actually licensing their indexes to each other, the results are far more homogenous. Consequently, a meta-search engine such as DogPile.com doesn't yield you much more than you would get using Google directly. And with the major search engines working tirelessly to improve relevance of search results while also rolling out new features, meta-search simply feels far less compelling.

In the area of business content, the list of quality content suppliers is limited, and most were smart enough not to enter into exclusive deals with any one aggregator. As a result, the big business content aggregators began to look very similar in terms of content offered. That left them to compete on price, an unattractive way to do business, which is why they've largely shifted their strategy to focus on value-added tools.

But aggregation does actually make business sense in the area of job boards. This remains a balkanized market with lots of players of all shapes and sizes. Given the costs involved, it's a rare company that would place a job listing on more than one of the big job boards at a time. Relatively high costs have therefore allowed specialty and regional job boards to thrive, offering the benefits of more targeted markets and lower prices. Since job listings are scattered over a large number of both well-known and obscure job sites, this is a market ripe for aggregation, especially since the recent boom in online advertising provides a source of quick and easy revenue for these aggregators. Users of these aggregation sites get both comprehensiveness and convenience.

At the moment, the major job boards are regarding these aggregators as just added distribution for their listings. But, as other information providers have learned, as these aggregators grow and develop their own brands, the brands of the job boards will very likely get diminished as job hunters increasing tell employers they saw the job listing on, say, SimplyHired rather than Monster. And if history is any guide, as these aggregators grow more successful, there will be enormous pressure for at least a few of them to try to sell job listings directly. And if they've got the traffic, what's to stop them?

So, if I ran a major job board, I'd be far less sanguine about this new crop of companies. Because over time, aggregators become a source of aggravation for information providers. They get a free ride off our content, allowing them to build front-ends to original sources of information, and siphon off traffic from our own sites, with the potential to become competitors should they choose. That's why I suggest you keep your eyes peeled for aggregation activity in your market, especially if your content is involved. These free riders can put a real dent in your business.