Whether one is still employed, about to be laid off or scrambling to find a suitable job before the unemployment insurance runs out in a tough economy, there are plenty of reasons why one would want to make their time spent searching employment sites on line as efficient as possible. 
The less time you spend being distracted by all the other worries of unemployment and really focus on finding the jobs you want (rather than wading through a sea of jobs you don’t want), the better chance you have of having jobs offers to choose from.

For starters, you want to get an idea of how an site gets help wanted ads in the first place.  They may directly charge employers to place an ad, or they may index other sites such as the more traditional job posting sites like classified ads in newspapers.  The uniqueness of the content as well as how widely ranging the indexes are make a big difference in just how likely you are to get any real benefit from a search of employment sites.

It is also helpful to get an idea of just what sort of job you’re interested in pursuing.  Targeting prospective employers in your field is best accomplished when you have a clear idea of exactly what you want to do in your next job or which company you want to look for.  If you are willing to move to take the right job or don’t mind a commute, you’ll have a better chance in a more limited field.

On the other hand, with just a quick search, employment sites tend to preferentially feature ads from governmental and corporate sources.  If you want to work in one of those places, that’s great, but if you’d prefer to have a job closer to home or work for a small, local and independent business, you’d do better to use other methods of searching. 

While there are websites that specialize in local listings, such as craigslist, the most effective way to find such local jobs is to simply get out and start pounding the pavement and hand your flawless resume off at local businesses you’d like to work for, whether they’re currently advertising or not.

Another highly rewarding method of finding meaningful local work (other than conducing searches of an employment site) is using your social network to find out just who might need a problem solved or a position filled that you can help out with.  Even with local list searches, employment sites don’t give you the advantages a spontaneous, face to face contact allows.

Making a search on employment sites actually work for you is a combination of choosing your search criteria according to the job you know you want and the skills you already posses.  By very honestly matching these, you vastly increase your chances of finding meaningful matches when searching employment sites.