The big job websites will often tell you to upload your CV so the top companies can headhunt you, or they will force you register an account with them and upload your CV just to apply for a job placed on their website. They make it sound like they are providing a great service to you that will help you advance your career. The truth is far from it.
The big job websites make a huge amount of money selling YOUR personal information. Of course, they don't tell you this! Most candidates assume the job websites are making their money by selling advertising - ie. charging companies to place job vacancies on their websites. While it is true they do this, they often provide heavy discounts on their advertised prices. Some websites even allow free posting of job advertisements to help attract more candidates. The big money in online recruitment is made selling access to candidates personal data.
Well, it's hardly the top companies looking to headhunt the best talent. The reality is your personal information is being brought by 1,000s of recruitment agencies and so called "recruitment consultants". Why? It's very simple: if an agency puts your CV on the desk of a hiring company and that company hires you, that agency can get up to 30% (sometimes more) of your first year's salary as their fee! Therefore, agencies are keen to get the very latest candidates to offer their clients.
Online recruitment is driven by agencies recuiring fresh candidates. That is the sole reason you are encouraged to submit your CV online. If the job websites get fresh candidates the agencies will keep on paying to access those candidates. The recruitment agencies are more akin to cold calling salesman than career consultants. They spend all day on the phones trying to match up candidates and vacancies to hopefully cash in. Very little concern is given to the suitability of the candidate to the job by the agencies. Their entire business revolves around subitting as many CVs for as many jobs as possible and hoping one of them gets hired.
Once you have submitted your CV to the job websites, that data is made available to the recruitment agencies. They scour the big job boards, sometimes using automated software, and create their own databases of candidates. They even repost your information on their own websites or internal intranets. It doesn't matter if you remove your personal information from the job website you submitted your CV to, because it will continue to existing in 1,000s of other databases of which you have no control and no guarantee your personal information will be protected. The job websites will claim this doesn't happen and their terms and conditions prohibit their clients (the agencies) from doing this, but the truth is they do it and these terms are just there to provide legal cover to prevent them being sued. The job websites want to keep the agencies happy because they are paying a lot of money each month to access your personal data, so this practice is widespread and largely ignored.
Some recruitment consultants don't have clients who need their vacancies filling. Instead, they scour the job websites looking for companies who are advertising directly, then search the candidates they have paid for access to (and in their own collected databases) and contact the hiring company to say they have the "perfect" candidate for them. Sometimes they contact the candidates and say they [already] have a client who is keen to meet them. Other times the candidate is never told their information has been submitted to a company. The hiring company is lead to believe the candidate has been vetted and is known to the agency and the candidate is lead to believe the hiring company has taken specific interest in them. The truth is the agency just matched up a candidate to a job and is hoping to get a fat payout for around ten minutes work. Because the process of matching candidates and jobs is very easy if they have access to databases of candidates, the whole online recruitment industry becomes a numbers game where the agencies are racing to be the first to get the candidates CV infront of a prospective employer. It's not uncommon for the same employer to recieve the same CV from many different agencies - all claiming to know and vouch for the candidate. This can have a very negative impact on that candidates credibility and success of landing the job.